*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19781
19791
19800
19810
19820
19830
19841
19850
19863
19870
19880
19890
19902
19910
19926
19934
19942
19951
19960
19970
19981
199928
20000
20018
20020
20030
20040
20050
20062
20070
20081
20091
20103
20113
20121
20137
20149
201511
20167
20177
20183
20199
20200
Total122