*Excludes Observations that spanned multiple years

Pre 19709
19700
19710
197269
197322
19740
19751
19761
19770
19780
19791
19803
19810
19821
198311
19849
198529
198687
1987140
1988232
198982
1990182
1991393
1992269
1993199
1994110
1995183
199673
199784
199860
1999123
200079
200190
200279
200391
2004152
2005206
2006112
2007128
2008111
200993
2010133
2011138
2012123
2013118
2014128
2015115
2016148
2017106
20183
20190
Total4526