Here are previous factorisations by year and month:

2012: April March February January
2011: December November October September August July June May April March February January
2010: December November October September August July June May April March February January
2009: December November October September August July June May April March February January
2008: December November October September August July June May April March February January
2007: December November October September August July June May April March February January
2006: December November October September August July June May April
2005: November October September August July June May April March February January
2004: December November October September August July June May April March
2003: December November

©2012 Bob Bäckström