The Dow Jones Industrial Average (DJINDICES:^DJI) is one of the oldest and most followed market barometers around the world. Of course, even the oldest index in the world isn't without its shortcomings. It's needed to be updated a number of times as more relevant companies have wiggled their way into the index, and it's basis solely on share price, not market cap, has left some investors scratching their head as to its relevance.

The Dow's best attribute
One area where the Dow is most definitely relevant is with dividend seeking investors. There's nothing that makes an income investor happier than scurrying through the list of the Dow's top paying dividend stocks. And it should be noted that there are nearly 2,000 companies paying a dividend in some form or shape now, but Dow components have a special draw for income investors that few other companies have. This could be due to their status as belonging to the Dow and requiring index funds that track the index to buy in, or, more likely, it's because these are stable businesses and they've demonstrated decades of steady growth.

Source: Chris Potter, Flickr.

Here are a few other dividend facts about the Dow that you may not be aware of:

  • Every single Dow component has raised their dividend over the past 10 years. Even components that were forced to at one point drastically cut their dividend due to the recession (JPMorgan Chase and General Electric) or a large strategic purchase (Pfizer) are paying out more now on a quarterly basis than they were 10 years ago. I should note that Visa and Cisco Systems were excluded since they only began paying a dividend within the past few years -- but if it makes you feel any better their payouts are up substantially, too, since they started!
  • Not only has every Dow component raised its dividend over the past decade, but excluding the one company whose dividend increase over that time period is light years ahead of its peers the average Dow component is paying out 198% more than what it did at this time in 2004.
  • 20 out of 30 Dow components have raised their payout by triple digits over the trailing decade with 11 companies topping the 200% mark, eight surpassing 300% dividend growth, and five lifting their payout by better than 400%!

In other words, the Dow is an income investor's paradise!

The Dow's fastest growing dividend
But can you guess which company has rocketed to the forefront and raised its dividend faster than any other Dow component over the trailing decade? I've already given you a clue that the preceding five companies aren't in contention, so that narrows your selection down to the remaining 25 companies.

Think for a moment which company you believe would fit the bill as the Dow component with the fastest growing dividend over the past decade.

Got it?

Did you say McDonald's (NYSE:MCD)? If you did, you managed to pick a company that's grown its dividend by an impressive 489% over the trailing decade, from just $0.55 per year to $3.24 annually now. McDonald's has benefited by adapting its menu to include healthier food and beverage choices and also offer consumers more price points to choose from. Also a big part of its success was the redesign of its interior restaurants which made them more inviting to families within the U.S. However, its 489% payout increase was only good enough for fourth-best on the list.

Source: IBM.

Raise your hand if Big Blue, IBM (NYSE:IBM), came to mind. It's one of Warren Buffett's largest holdings, and this Buffett character has demonstrated his ability to know a thing or two about stock-picking and finding steady income generators over the years. While IBM has struggled a bit recently with the transition to mobile-based products, its efforts to boost R&D and focus on cloud and big data are expected to result in much improved cash flow in the latter half of the decade. To add, IBM has also increased its payout by a whopping 494% since 1994. But, like McDonald's it wasn't the top dog in dividend increases.

How about the home-improvement giant Home Depot (NYSE:HD)? Home Depot has been able to take advantage of both sides of the aisle, benefiting from low lending rates and a rebound in the commercial and homebuilding sector, which has boosted sales to contractors, while also basking in steady remodeling growth from the consumer side of the equation. With a high barrier to entry in the home improvement market, Home Depot has built a pretty commanding market share lead over its primary rival. The end result has been an astronomical 571% increase in its payout over the past decade to $0.47 per quarter compared to just $0.07 previous. And still, this isn't good enough for the top spot!

In actuality, the fastest growing dividend within the Dow is (drumroll, please) ...

Source: National Cancer Institute, Wikimedia Commons. 

UnitedHealth Group (NYSE:UNH).

I told you that you weren't going to guess it!

Before 2009, UnitedHealth Group didn't do a particularly good job of going the extra mile for shareholders. In fact, between 2001 and 2009 it paid out just a $0.03 annual payout per year. It was the equivalent of dropping a marble on the ground and seeing if it registered on the Richter Scale. However, in 2010 UnitedHealth Group started to get serious, and income investors took notice.

Since 2010, UnitedHealth Group, the nation's largest health-benefits provider, has delivered a payout increase in each successive year. What was once a $0.03 annual payout is now a $0.28 quarterly payout, translating to an increase of 3,633% over the past decade!

Moreover, it's quite possible that this dividend could be primed to head even higher. Obamacare is creating a number of long-term opportunities for UnitedHealth including the ability to sign up uninsured people who are now compelled to purchase health insurance by law, as well as an ongoing push toward electronic health management services where its Optum subsidiary could thrive. It's going to be tough for UnitedHealth to top its past decade of growth in the coming years, but it could very easily remain one of the fastest growing dividend payers within the Dow moving forward.