After 1 million units shipped in Q2 2014, the market has now grown to 5.3 million. Of course, the steep rise in the popularity of smart wearables, is more of a global trend than anything else, but the fact that Apple brought a serious boost to the niche is out of question.
http://www.gsmarena.com/the_apple_watch_might_be_doing_better_than_expected_with_a_whopping_75_percent_market_share-news-13206.php