*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19757
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19908
19910
19923
19930
19940
19953
19960
19976
19980
19993
20007
20013
20020
20031
20045
20053
20062
20070
20080
20092
20100
20110
20121
20130
20140
20150
20160
20170
Total54