20 instances from 4 years 2018 - 3 instances Jan Feb Mar Apr May Jun 21 3 Jun 21, 2018 3 instances 03:28:30 03:29:05 03:29:59 Jul Aug Sep Oct Nov Dec 2017 - 4 instances Jan Feb Mar Apr May Jun 21 2 Jun 21, 2017 2 instances 20:20:10 20:23:01 Jul Aug Sep Oct 2 Nov Dec 25 2016 - 12 instances Jan Feb Mar Apr May Jun 20 3 Jun 20, 2016 3 instances 09:41:24 10:07:34 12:30:35 Jul Aug Sep 19 3 Sep 19, 2016 3 instances 17:14:01 17:17:40 17:20:18 Oct 1 2 Oct 1, 2016 2 instances 01:40:47 01:45:41 3 3 Oct 3, 2016 3 instances 17:20:55 17:25:45 17:26:18 Nov Dec 30 2015 - 1 instance Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 18