Graph
Year | Totals | Observation hours |
---|---|---|
1900 | 5 | 5:30 |
1980 | 206 | 2:00 |
1981 | 4046 | 143:25 |
1982 | 6355 | 100:04 |
1983 | 5004 | 76:05 |
1984 | 12555 | 157:55 |
1985 | 5228 | 193:05 |
1986 | 25912 | 180:40 |
1987 | 4864 | 99:15 |
1988 | 2650 | 216:00 |
1989 | 21018 | 269:46 |
1990 | 15813 | 262:45 |
1991 | 28569 | 405:47 |
1992 | 23351 | 645:00 |
1993 | 55715 | 397:58 |
1994 | 12783 | 286:00 |
1995 | 19787 | 224:45 |
1996 | 126738 | 328:00 |
1997 | 34720 | 356:45 |
1998 | 38911 | 339:30 |
1999 | 25148 | 267:15 |
2000 | 8298 | 261:30 |
2001 | 33023 | 525:35 |
2002 | 41716 | 526:15 |
2003 | 118011 | 567:15 |
2004 | 42663 | 455:05 |
2005 | 86428 | 601:15 |
2006 | 52884 | 389:55 |
2007 | 29211 | 432:55 |
2008 | 22040 | 525:55 |
2009 | 27398 | 399:05 |
2010 | 27993 | 249:40 |
2011 | 78944 | 319:15 |
2012 | 17374 | 231:35 |
2013 | 79644 | 270:55 |
2014 | 14340 | 291:35 |
2015 | 23721 | 177:30 |
2016 | 74628 | 230:15 |
2017 | 18723 | 250:05 |
2018 | 60527 | 318:16 |
2019 | 33685 | 584:19 |
2020 | 29080 | 587:17 |
2021 | 285148 | 646:27 |
2022 | 51757 | 477:05 |