Fiscal year (FY) 2013 Apple sold 150M iPhones. FY2014 they're on track to sell 170-180M depending on when the iPhone 6 hits the market. Year-over-year iPhone unit sales are growing 15-20% But since the overall smartphone market is growing at a faster rate, iPhone's market share is declining.
As others have already pointed out, market share is only one way of analyzing what is happening in the phone market. It's not the most important metric, yet it's the easiest to "calculate" (guess), so gets the most attention among the press & punditry.
Despite the tendency to predict doom & gloom for Apple, few believe that they are going to sell fewer iPhones in FY2015. There is an increasingly large number of very satisfied iPhone users, many of whom are eagerly anticipating the next version. I don't think there's any doubt that Apple will sell >200M iPhones in FY2015. That's easily >$100B worth of phones. With revenue like that, Apple doesn't need to bust a gut just for market share.
And you just made my point. Somewhat. Numbers for a couple more years back would really make it. Because they would back up that Apple isn't selling any fewer phones than now.