Graph
Year | Totals | Observation hours |
---|---|---|
1900 | 0 | 5:30 |
1980 | 0 | 2:00 |
1981 | 836 | 143:25 |
1982 | 1691 | 100:04 |
1983 | 921 | 76:05 |
1984 | 4368 | 157:55 |
1985 | 2114 | 193:05 |
1986 | 3771 | 180:40 |
1987 | 1039 | 99:15 |
1988 | 1460 | 216:00 |
1989 | 4322 | 269:46 |
1990 | 1256 | 262:45 |
1991 | 2681 | 405:47 |
1992 | 10099 | 645:00 |
1993 | 10778 | 397:58 |
1994 | 9812 | 286:00 |
1995 | 9322 | 224:45 |
1996 | 3890 | 328:00 |
1997 | 8079 | 356:45 |
1998 | 21035 | 339:30 |
1999 | 6405 | 267:15 |
2000 | 5119 | 261:30 |
2001 | 6009 | 525:35 |
2002 | 4875 | 526:15 |
2003 | 16601 | 567:15 |
2004 | 27413 | 455:05 |
2005 | 18642 | 601:15 |
2006 | 6411 | 389:55 |
2007 | 6320 | 432:55 |
2008 | 13087 | 525:55 |
2009 | 10108 | 399:05 |
2010 | 11856 | 249:40 |
2011 | 25163 | 319:15 |
2012 | 9759 | 231:35 |
2013 | 26227 | 270:55 |
2014 | 6512 | 291:35 |
2015 | 3704 | 177:30 |
2016 | 6982 | 230:15 |
2017 | 9736 | 250:05 |
2018 | 7216 | 318:16 |
2019 | 19446 | 584:19 |
2020 | 12169 | 587:17 |
2021 | 21467 | 646:27 |
2022 | 18781 | 479:35 |