Graph
Year | Totals | Observation hours |
---|---|---|
1972 | 21 | 31:00 |
1973 | 0 | 18:15 |
1974 | 0 | 7:45 |
1975 | 0 | 18:30 |
1976 | 0 | 66:30 |
1977 | 33 | 23:45 |
1978 | 5 | 116:45 |
1979 | 7 | 71:45 |
1980 | 46 | 109:00 |
1981 | 4 | 78:00 |
1982 | 0 | 39:00 |
1983 | 8 | 71:00 |
1984 | 1 | 30:15 |
1985 | 35 | 98:00 |
1986 | 6 | 41:30 |
1987 | 0 | 42:15 |
1988 | 0 | 55:00 |
1989 | 0 | 47:15 |
1990 | 0 | 33:00 |
1991 | 2 | 18:00 |
1992 | 1 | 28:30 |
1993 | 14 | 25:45 |
1994 | 0 | 40:00 |
1995 | 0 | 15:15 |
1996 | 0 | 5:00 |
1997 | 0 | 26:30 |
1998 | 11 | 20:00 |
1999 | 0 | 26:45 |
2000 | 0 | 27:30 |
2001 | 0 | 23:00 |
2002 | 0 | 26:55 |
2003 | 1 | 37:45 |
2004 | 0 | 30:10 |
2005 | 1 | 34:00 |
2006 | 1 | 41:33 |
2007 | 0 | 83:14 |
2008 | 2 | 56:33 |
2009 | 6 | 76:07 |
2010 | 0 | 52:50 |
2011 | 2 | 80:30 |
2012 | 6 | 94:05 |
2013 | 1 | 66:27 |
2014 | 0 | 41:10 |
2015 | 0 | 49:05 |
2016 | 0 | 19:00 |
2017 | 2 | 123:39 |
2018 | 7 | 89:34 |
2019 | 3 | 98:07 |
2020 | 0 | 108:43 |
2021 | 0 | 4:45 |