*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19851
19860
19874
19880
19890
19901
19910
19921
19931
19942
19951
19960
19973
199814
19991
20000
20012
20020
20030
20044
20053
20062
20070
20080
20091
20103
20111
20120
20130
20140
20154
20162
20170
Total51