*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19721
19730
19740
19751
19760
19770
19780
19791
19800
19810
19820
19831
19840
19853
19860
19875
198829
198910
19902
19916
19921
19936
19940
19951
19961
19975
19980
199910
20008
200123
20023
20031
20040
20056
20060
20070
20082
20090
201012
201112
20124
20132
20145
20152
201616
201716
20180
20190
Total195