*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19840
19850
19861
19870
19880
19890
19900
19911
19921
19930
19943
19951
19960
19970
19980
19990
20000
20017
20020
2003691
2004121
20051751
200641
2007279
200878
20091090
20107
20113
20120
20130
20143
20155
20167
20176
20180
Total4098