Graph
Year | Totals | Observation hours |
---|---|---|
1900 | 0 | 5:30 |
1980 | 0 | 2:00 |
1981 | 12 | 143:25 |
1982 | 48 | 100:04 |
1983 | 676 | 76:05 |
1984 | 887 | 157:55 |
1985 | 162 | 193:05 |
1986 | 1322 | 180:40 |
1987 | 60 | 99:15 |
1988 | 210 | 216:00 |
1989 | 2756 | 269:46 |
1990 | 750 | 262:45 |
1991 | 1556 | 405:47 |
1992 | 4338 | 645:00 |
1993 | 3076 | 397:58 |
1994 | 2799 | 286:00 |
1995 | 3998 | 224:45 |
1996 | 4606 | 328:00 |
1997 | 1825 | 356:45 |
1998 | 3686 | 339:30 |
1999 | 7530 | 267:15 |
2000 | 1081 | 261:30 |
2001 | 2943 | 525:35 |
2002 | 1657 | 526:15 |
2003 | 6110 | 567:15 |
2004 | 3710 | 455:05 |
2005 | 2856 | 601:15 |
2006 | 4588 | 389:55 |
2007 | 2564 | 432:55 |
2008 | 1507 | 525:55 |
2009 | 3297 | 399:05 |
2010 | 1573 | 249:40 |
2011 | 3680 | 319:15 |
2012 | 1543 | 231:35 |
2013 | 3152 | 270:55 |
2014 | 1161 | 291:35 |
2015 | 2396 | 177:30 |
2016 | 3543 | 230:15 |
2017 | 1757 | 250:05 |
2018 | 3039 | 318:16 |
2019 | 2347 | 584:19 |
2020 | 2256 | 587:17 |
2021 | 2736 | 646:27 |
2022 | 4136 | 477:05 |