*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19910
19920
19930
19940
19953
19960
19970
19980
19990
20000
20011
20020
20031
20045
20055
20066
20076
200830
200973
201056
201139
201239
201337
201428
201519
20169
20170
Total357