Investing isn't easy. Even Warren Buffett counsels that most investors should invest in a low-cost index like the S&P 500. That way, "you'll be buying into a wonderful industry, which in effect is all of American industry," he says.

But there are, of course, companies whose long-term fortunes differ substantially from the index. In this series, we look at how individual stocks have performed against the broad S&P 500.

Step on up, West Pharmaceutical Services (NYSE: WST).         

West Pharmaceutical Services shares have roughly matched the S&P 500 over the last quarter-century:

Wstsp

Source: S&P Capital IQ.

Since 1987, shares have returned an average of 10.1% a year, compared with 9.7% a year for the S&P (both include dividends). One thousand dollars invested in the S&P in 1987 would be worth $19,200 today, and, naturally, about the same in West Pharmaceutical Services.

Dividends accounted for a lot of those gains. Compounded since 1987, dividends have made up about half of West Pharmaceutical Services' total returns. For the S&P, dividends account for 39% of total returns.

Now have a look at how West Pharmaceutical Services earnings compare with S&P 500 earnings:

Wstearnings

Source: S&P Capital IQ.

Again, pretty average. Since 1995, West Pharmaceutical Services earnings per share have increased by 5.6% per year, compared with 6% a year for the broader index. 

What's that meant for valuations? West Pharmaceutical Services has traded for an average of 20 times earnings since 1987 -- below the 24 times earnings of the broader S&P 500.

Through it all, shares have been mediocre performers over the last quarter-century.  

Of course, the important question is whether that will continue. That's where you come in. Our CAPS community currently ranks West Pharmaceutical Services with a three-star rating (out of five). Care to disagree? Leave your thoughts in the comment section below, or add West Pharmaceutical Services to My Watchlist.