y = -0.0025x + 6.654
R² = 0.0093
Bam. ABV is not rising and with a regression slope of -0.0025x is in a bit of a decline over the last four years. This is an ever so slight decline and is reflected in the fairly constant average ABV per year. What is interesting in this data is the increase in variance and low R². The yearly standard deviation has increased from 0.5 in 2012 to 1.2 in 2016.
Just the numbers
Why the greater variance? I see it as fewer beers taking the middle ground for an IPA, around 6.5 ABV, and more trying to differentiate with either flirting in the DIPA range or dropping down to a session level. Either way this is good to see more variety, even within just the IPA range, and not just a race to make a stronger beer.