*Excludes Observations that spanned multiple years

Pre 19703
19702
19715
1972147
197385
19740
19750
19761
19770
19781
19790
19801
19810
19824
19833
198463
198526
1986150
1987187
1988262
1989265
1990167
1991244
1992125
1993346
1994177
1995130
1996263
1997365
199850
1999105
2000113
200192
200234
2003176
2004170
2005186
2006166
2007161
2008190
2009180
2010154
2011164
2012139
2013169
2014174
2015176
2016170
2017144
20180
Total5935