18 instances from 6 years 2021 - 1 instance Jan Feb Mar Apr May Jun 26 Jul Aug Sep Oct Nov Dec 2020 - 1 instance Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov 12 Dec 2019 - 1 instance Jan Feb Mar Apr May Jun 22 Jul Aug Sep Oct Nov Dec 2018 - 1 instance Jan 12 Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2017 - 2 instances Jan 8 Feb Mar Apr May Jun 26 Jul Aug Sep Oct Nov Dec 2016 - 12 instances Jan Feb Mar Apr May Jun 21 22 Jul Aug Sep 20 4 Sep 20, 2016 4 instances 15:51:13 16:41:28 21:22:36 21:40:03 Oct 1 2 Oct 1, 2016 2 instances 22:33:09 23:46:48 4 3 Oct 4, 2016 3 instances 17:12:29 17:40:39 20:18:34 Nov Dec 30