*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19791
19800
19810
19820
19830
19840
19850
19860
19872
198820
19890
19900
19910
19922
19930
19941
19950
19961
19971
19981
19990
20002
20011
20020
20034
20045
20053
20061
20071
20085
20091
201029
201122
20121
20132
20147
20153
20164
20173
20180
Total123