*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19910
19921
19930
19941
19950
19960
19975
19980
19991
20000
20010
20020
20030
20040
20054
20060
20070
20081
20090
201025
201110
20121
20130
20140
20150
20160
20170
Total49