The closest I can Find is the W3school's
Browser OS chart, it basically measures what the Marketshare of OS use is by using browser meta. From What I can see it goes back to 2003, not exactly ten years, and it lists a 1.8% share for Mac in March of '03, which has risen to 7.6% last month. now obviously this doesn't account for the rise in ISP contracts in the past 7 years or the increase in availability of internet, but it does show that there is indeed a fair amount of increase in Mac user share.