20 instances from 4 years 2018 - 3 instances Jan Feb Mar Apr May Jun 21 3 Jun 21, 2018 3 instances 03:34:26 03:35:37 03:36:56 Jul Aug Sep Oct Nov Dec 2017 - 4 instances Jan Feb Mar Apr May Jun 21 2 Jun 21, 2017 2 instances 20:22:57 20:25:45 Jul Aug Sep Oct 2 Nov Dec 25 2016 - 12 instances Jan Feb Mar Apr May Jun 20 4 Jun 20, 2016 4 instances 08:50:11 09:10:41 11:25:55 13:20:30 Jul Aug Sep 19 3 Sep 19, 2016 3 instances 17:16:46 17:20:24 17:23:10 Oct 1 3 3 Oct 3, 2016 3 instances 17:23:40 17:28:30 17:29:03 Nov Dec 30 2015 - 1 instance Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 18