Aside from the overall return (1,598,284%), there are three important things you should notice here. First, notice how Berkshire has a tendency to underperform the S&P 500 in many of the market's best years, such as 2009, 2003, 1999, and 1996, just to name a few. This isn't a universal truth (look at 2013 and 2014), but historically this has been the case more times than not. Warren Buffett openly acknowledges this, as his priority is safe, dependable growth -- not catching the next big thing.
Second, notice that the S&P 500 had 11 negative years out of the past 50. Then take a look at Berkshire's return in all of these years. The company outperformed the market in all but two of them -- a big contributor to Berkshire's long-term success.