Graph
Year | Totals | Observation hours |
---|---|---|
1972 | 0 | 31:00 |
1973 | 0 | 18:15 |
1974 | 2 | 7:45 |
1975 | 0 | 18:30 |
1976 | 0 | 66:30 |
1977 | 0 | 23:45 |
1978 | 0 | 116:45 |
1979 | 140 | 71:45 |
1980 | 55 | 109:00 |
1981 | 43 | 78:00 |
1982 | 21 | 39:00 |
1983 | 39 | 71:00 |
1984 | 5 | 30:15 |
1985 | 198 | 98:00 |
1986 | 25 | 41:30 |
1987 | 137 | 42:15 |
1988 | 119 | 55:00 |
1989 | 164 | 47:15 |
1990 | 1 | 33:00 |
1991 | 124 | 18:00 |
1992 | 278 | 28:30 |
1993 | 30 | 25:45 |
1994 | 64 | 40:00 |
1995 | 70 | 15:15 |
1996 | 0 | 5:00 |
1997 | 23 | 26:30 |
1998 | 4 | 20:00 |
1999 | 12 | 26:45 |
2000 | 66 | 27:30 |
2001 | 956 | 23:00 |
2002 | 519 | 26:55 |
2003 | 328 | 37:45 |
2004 | 558 | 30:10 |
2005 | 1164 | 34:00 |
2006 | 478 | 41:33 |
2007 | 417 | 83:14 |
2008 | 41 | 56:33 |
2009 | 134 | 76:07 |
2010 | 34 | 52:50 |
2011 | 115 | 80:30 |
2012 | 3233 | 94:05 |
2013 | 72 | 66:27 |
2014 | 197 | 41:10 |
2015 | 1099 | 49:05 |
2016 | 318 | 19:00 |
2017 | 2931 | 123:39 |
2018 | 2911 | 89:34 |
2019 | 3071 | 98:07 |
2020 | 6494 | 108:43 |
2021 | 21 | 1:30 |