*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19731
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19891
19900
19910
19920
19930
19941
19950
19960
19970
19980
19990
20000
20010
20020
20030
20040
20050
20060
20070
20081
20092
20100
20112
20120
20130
201415
201521
2016594
20172
20180
Total640