The first 4 rounds are slightly skewed towards Offense:
2010: 2 Offense, 3 Defense
2011: 3 Offense, 1 Defense
2012: 2 Offense, 3 Defense
2013: 2 Offense, 1 Defense
2014: 3 Offense, 2 Defense
The 5th through 7th rounds are also balanced with two years (2011 and 2012) being HUGE exceptions...