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 13 Dec 2019 - 1 instance Jan Feb Mar Apr May Jun 22 Jul Aug Sep Oct Nov Dec 2018 - 1 instance Jan 24 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 15:51:25 16:41:40 21:22:49 21:40:15 Oct 1 2 Oct 1, 2016 2 instances 22:33:22 23:47:00 4 3 Oct 4, 2016 3 instances 17:12:42 17:40:52 20:18:46 Nov Dec 30