Difficult was up to 232.83547290 and after hashrate down to 0.58 Gh. 2,5 minutes per one block is 25+ minutes per block. If in bitcoin network hashrate down so quick - next difficult retargedet in 2016*100 minutes = 140 days. Recall Namecoin in 2011 year.
if hashrate bitblock will increase 2x every period of retarget diff, time to find block will 2,5 minutes/2 = 1,25 minutes.