I'm not so sure. Linux has really been taking off since early 2006.
http://www.itwire.com.au/content/view/8327/1090/
2003 - It's the year of the Linux desktop!
2004 - It's the year of the Linux desktop!
2005 - It's the year of the Linux desktop!
2006 - It's the year of the Linux desktop!
2007 - It's the year of the Linux desktop... again?