20 instances from 4 years 2018 - 3 instances Jan Feb Mar Apr May Jun 21 3 Jun 21, 2018 3 instances 03:31:14 03:35:31 03:36:50 Jul Aug Sep Oct Nov Dec 2017 - 4 instances Jan Feb Mar Apr May Jun 21 2 Jun 21, 2017 2 instances 20:22:50 20:25:39 Jul Aug Sep Oct 2 Nov Dec 25 2016 - 12 instances Jan Feb Mar Apr May Jun 20 4 Jun 20, 2016 4 instances 08:50:21 09:10:31 11:26:32 13:20:40 Jul Aug Sep 19 3 Sep 19, 2016 3 instances 17:16:40 17:20:18 17:23:04 Oct 1 3 3 Oct 3, 2016 3 instances 17:23:34 17:28:24 17:28:56 Nov Dec 30 2015 - 1 instance Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 18