May 24, 2016. Difficulty rose by +2.60% to 199.31B from 194.25B.
Change
+2.60%
New difficulty
199.31B
Period length
13.6 days
Network hashrate then (7-day)
1.5 EH/s
Bitcoin price then
$443
Hashprice then
$1,122/PH/day
The 2,016 blocks before it took 13.6 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 2.60%: an ordinary adjustment. For every machine on the network that is a pay cut of the same size until the next retarget.