Dividend investors would be wise to focus not just on a stock's current yield, but also on the long-term growth potential of its dividends. That's because strong businesses that consistently raise their dividend payouts reward shareholders with a steadily rising income stream that essentially equates to a raise every year. And, well, who doesn't like a raise?

But there are other reasons to value dividend growth so highly, and they're well supported by research. For instance, a study by C. Thomas Howard  published in Advisor Perspectives found that for every percentage point a stock's yield rises, its annual return increases by 0.22 percentage points if it's a large cap, 0.25 if it's a mid cap, and 0.46 if it's a small cap. Even better, Howard found that dividend-growing stocks outperformed dividend cutters by 10 percentage points per year from 1973 to 2010 and beat both flat- and no-dividend stocks. And the icing on the cake is that Howard showed that this outperformance came with a third less volatility. Higher returns, less volatility-induced stress, and a steadily growing income stream -- what's not to love?

With that in mind, here are five stocks that have grown their dividends by 15% or more over the last year:

Company

1-Year Dividend Growth Rate

Halliburton (NYSE: HAL)

19.4%

VF (NYSE: VFC)

19.4%

Magellan Midstream Partners (NYSE: MMP)

19.2%

Service Corp. (NYSE: SCI)

19%

Nike (NYSE: NKE)

15.7%

Source: S&P Capital IQ.

Halliburton is one of the world's largest providers of products and services to the energy industry, with more than 75,000 employees in approximately 80 countries. The company serves the upstream oil and gas industry throughout the lifecycle of the reservoir -- from locating hydrocarbons and managing geological data, to drilling and formation evaluation, well construction and completion, and optimizing production through the life of the field. CAPS participants have awarded Halliburton with a top five-star rating, and the company is paying out a growing 1% dividend.

VF is an apparel and footwear powerhouse, with a diverse portfolio of brands including The North Face, Nautica, Timberland, JanSport, Wrangler, and Lee, among others. VF sports a five-star rating in CAPS and is yielding 1.8%.

Magellan Midstream Partners owns the longest refined petroleum products pipeline system in the United States. It can tap into more than 40% of the nation's refining capacity and store 80 million barrels of petroleum products such as gasoline, diesel fuel, and crude oil. Magellan's primarily fee-based business generates strong cash flows that the MLP passes on to its investors in the form of a 3.9% cash distribution, helping Magellan earn a four-star rating in CAPS.

Service Corp. is North America's leading provider of death-care products and services. Through its network of more than 1,800 funeral homes and cemeteries, Service Corp. provides funeral, cremation, and cemetery services to hundreds of thousands of families every year. Service Corp. has a three-star ranking on CAPS and offers investors a 1.5% yield.

Nike is the global leader in athletic footwear, apparel, equipment, and accessories. Its tremendously valuable collection of brands -- from its iconic namesake Nike brand, to Jordan, Converse, and Hurley -- has helped propel the company to market-crushing long-term gains. This Fool favorite has a top five-star CAPS rating, and offers investors a growing 1.2% dividend.

The Foolish bottom line
Had you invested in these companies a year ago, you would have enjoyed total dividend increases ranging from 15% to 19%. That level of growth would provide a substantial boost to just about any investor's dividend income. But more important to investors today is to identify the companies that will grow their dividends substantially in the years ahead. If you're interested in hearing about some excellent companies that are likely to boost their dividends from this point forward, I'd like to offer you a brand-new free report from The Motley Fool's expert analysts called "Secure Your Future With 9 Rock-Solid Dividend Stocks." Today I invite you to download it at no cost to you. To discover the identities of these companies before the rest of the market catches on, you can access this valuable free report by simply clicking here now.

Joe Tenebruso manages a Real-Money Portfolio for The Motley Fool and is an analyst on the Fool's Stock Advisor and Supernova premium service teams. You can connect with him on Twitter: @Tier1Investor. Joe has no position in any stocks mentioned.

The Motley Fool recommends Halliburton, Magellan Midstream Partners, and Nike and owns shares of Nike. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.