*Excludes Observations that spanned multiple years

Pre 1970151
197027
197133
197259
197370
197487
197568
197665
197757
197860
1979100
1980143
1981155
1982179
1983190
1984216
1985240
1986273
1987196
1988202
1989315
1990415
1991333
1992405
1993420
1994352
1995342
1996349
1997338
1998396
1999431
2000363
2001430
2002436
2003452
2004591
2005565
2006575
2007541
2008590
2009618
2010681
2011549
2012535
2013411
2014420
2015503
2016148
20174
20180
20193
20202
20210
Total15084