*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19761
19770
19780
19791
19801
19810
19820
19830
19840
19850
19860
19870
19880
19890
19906
19910
19926
19930
19941
19953
19963
19971
19980
19995
20003
20016
20020
20036
20045
200511
20061
20073
20087
20090
20100
20112
20127
20130
20140
20150
20160
20170
Total79