*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19721
19730
19740
19751
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19872
19880
19890
19900
19910
19920
19931
19940
19951
19961
19971
19980
19990
20000
20015
20021
20031
20040
20056
20060
20070
20082
20090
201012
201112
20124
20132
20145
20152
201616
201716
20180
Total92