10/31/2004-12/31/2006 +15.55% (annualized)
10/31/2004-12/31/2007 +30.70% (annualized)
10/31/2004-12/31/2008 +31.68% (annualized)
10/31/2004-04/30/2009 +34.40% (annualized)

2005 -3.23%
2006 +23.33%
2007 +70.27%
2008 +34.92%
2009 +72.80% (annualized, based on last 4 months)

Predictions (Based on exponential regression line, round to 0.2%)

12/31/2009 1.0%
12/31/2010 1.4%
12/31/2011 1.8%
12/31/2012 2.4%
12/31/2013 3.2%
12/31/2014 4.4%
12/31/2015 5.6%
12/31/2016 7.6%
12/31/2017 10.0%

Historically, 2007 was the year of the linux desktop. However, 2009 is currently surpassing 2007's growth rate.