*Excludes Observations that spanned multiple years

Pre 197047
197010
19710
197210
197372
1974286
1975372
1976238
197760
1978142
1979120
1980106
198199
198272
1983193
1984360
1985227
1986130
1987108
1988106
1989120
1990111
199170
199285
199388
199492
1995103
199699
199789
1998109
1999106
2000113
2001109
2002144
2003154
2004135
2005116
2006170
2007159
2008150
2009185
2010208
2011154
2012164
2013162
201416
20150
20160
20171
Total5970