*Excludes Observations that spanned multiple years

Pre 1970149
197022
197110
197222
197321
197441
197522
197626
197723
197830
197939
198023
198162
198268
1983135
1984178
1985148
1986248
1987300
1988274
1989236
1990245
1991330
1992311
1993292
1994318
1995348
1996368
1997387
1998429
1999485
2000540
2001577
2002545
2003707
2004650
2005663
2006706
20071337
2008881
20091092
20101206
2011873
20121009
2013835
201453
20150
20160
20170
Total17264