Afghan 'green-on-blue' attacks

2007 - 2 attacks, 2 Isaf soldiers dead
2008 - 2 attacks, 2 dead
2009 - 6 attacks, 10 dead
2010 - 6 attacks, 20 dead
2011 - 21 attacks, 35 dead
2012 (so far) - 36 attacks, 51 dead
Source: International Security Assistance Force (Isaf) via BBC:http://www.bbc.co.uk/news/world-asia-19632779