*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19910
19920
19930
19940
19950
19960
19970
19980
19990
20000
20010
20020
20031
20040
20050
20061
20073
20082
20095
201019
20118
201213
20135
20147
20157
20165
20170
Total77