*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19732
19740
19750
19760
19770
19781
19790
19800
19810
19820
19830
19840
19851
19860
19870
19881
19890
19900
19910
19920
19931
19940
19950
19960
19970
19980
19990
20001
20010
20020
20030
20040
20050
20060
20070
20082
20090
20104
20112
201227
20130
201415
201579
201656
20174
20180
Total196