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        22352       9445 
1999        13628       5230 
2000        38953      16115 
2001        39724      15443 
2002        31176      13968 
2003        58423      24301 
2004        46909      18002 
2005        82499      25385 
2006       106232      34067 
2007       194270      59955 
2008       116147      33176 
2009        95661      26944 
2010       110408      30795 
2011       162821      45132 
2012       154101      42688 
2013       227004      64638 
2014       562001     143512 
2015       780723     204615 
2016       664262     172338 
2017       563450     152361 
2018       361384     101475 
2019       879753     214832 
2020       632716     161220 
2021       853044     203123 
2022       634938     181754 
2023       574395     164235 
2024       642783     185108 
2025        70878      20043