*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19757
19766
19770
197814
19795
19803
19813
19828
198314
19847
198513
198611
19872
19884
19896
199022
19913
19921
19937
199451
199559
1996117
1997297
1998204
1999298
2000182
2001236
2002192
2003333
2004441
2005421
2006391
20071176
2008390
2009892
2010851
2011545
2012504
2013510
201419
20150
20160
20170
Total8245