Premiership Goal Fest

Probably everyone knows this already but a couple of data series caught my eye when finalising my fantasy spreadsheets for the 2012-13 Premier League season.
Since the current form of the Premiership started (in 1995) this season has seen the highest ever proportion of high-scoring matches (that is, over 2.5 goals). A not unrelated observation is that this season has seen the highest ever proportion of matches where neither team succeeded in getting a clean sheet.

Premiership Chart 2
Premiership Chart 1