Year Observations     Objects
1950            2          1 
1951            6          3 
1953            4          2 
1954            2          1 
1955            4          2 
1956            2          1 
1960            6          3 
1974            2          1 
1975            2          1 
1976            8          4 
1977            2          1 
1978            8          3 
1981            4          2 
1982           12          6 
1983            8          4 
1984            2          1 
1985            8          4 
1986            4          2 
1987            2          1 
1988           38         18 
1990           32         14 
1991          471        179 
1992          749        303 
1993         1313        489 
1994         1692        621 
1995         3117       1087 
1996         3008       1063 
1997         1961        676 
1998        22355       9446 
1999        13634       5232 
2000        38956      16116 
2001        39726      15444 
2002        31176      13968 
2003        58428      24303 
2004        46914      18004 
2005        82499      25385 
2006       106239      34069 
2007       194284      59958 
2008       116172      33183 
2009        95672      26947 
2010       110426      30800 
2011       162839      45137 
2012       154111      42690 
2013       227031      64645 
2014       563267     143774 
2015       781023     204673 
2016       664525     172394 
2017       563761     152424 
2018       361410     101483 
2019       879788     214842 
2020       632740     161227 
2021       853098     203138 
2022       634979     181766 
2023       574417     164241 
2024       642808     185115 
2025        71905      20308