*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
198413
198519
198619
198726
198830
198932
199051
199182
199282
199382
199483
199577
1996123
1997124
1998131
199995
2000180
2001104
2002121
2003123
2004126
2005154
2006179
2007353
2008305
2009390
2010371
2011328
2012345
2013316
201411
20150
20160
20170
Total4475