Graph
Year | Totals | Observation hours |
---|---|---|
1960 | 0 | 0:00 |
1961 | 0 | 0:00 |
1962 | 0 | 0:00 |
1963 | 0 | 0:00 |
1964 | 0 | 0:00 |
1965 | 0 | 0:00 |
1966 | 0 | 0:00 |
1967 | 0 | 0:00 |
1968 | 0 | 0:00 |
1969 | 0 | 0:00 |
1970 | 0 | 0:00 |
1971 | 0 | 0:00 |
1972 | 0 | 0:00 |
1973 | 0 | 0:00 |
1974 | 0 | 0:00 |
1975 | 0 | 0:00 |
1976 | 0 | 0:00 |
1977 | 118 | 791:25 |
1978 | 78 | 820:52 |
1979 | 58 | 934:10 |
1980 | 182 | 731:36 |
1981 | 157 | 944:01 |
1982 | 118 | 768:05 |
1983 | 140 | 673:25 |
1984 | 159 | 682:07 |
1985 | 161 | 775:03 |
1986 | 178 | 933:53 |
1987 | 291 | 1120:12 |
1988 | 341 | 1184:32 |
1989 | 449 | 1293:12 |
1990 | 303 | 944:40 |
1991 | 273 | 858:50 |
1992 | 358 | 759:26 |
1993 | 277 | 827:13 |
1994 | 292 | 1135:36 |
1995 | 215 | 1315:15 |
1996 | 310 | 1503:39 |
1997 | 324 | 1460:20 |
1998 | 423 | 1162:42 |
1999 | 595 | 1225:50 |
2000 | 196 | 1031:40 |
2001 | 387 | 1273:17 |
2002 | 525 | 1125:31 |
2003 | 650 | 1253:15 |
2004 | 735 | 1065:05 |
2005 | 757 | 1106:54 |
2006 | 351 | 964:46 |
2007 | 1488 | 1081:59 |
2008 | 1620 | 1099:59 |
2009 | 451 | 1282:49 |
2010 | 817 | 1288:05 |
2011 | 615 | 1234:15 |
2012 | 876 | 1364:55 |
2013 | 417 | 1352:29 |
2014 | 494 | 1299:50 |
2015 | 601 | 1223:30 |
2016 | 256 | 1409:54 |
2017 | 403 | 524:40 |
2018 | 315 | 1539:51 |
2019 | 707 | 1131:19 |
2020 | 606 | 1214:00 |
2021 | 11 | 33:30 |