*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19840
19850
19860
19870
198816
19890
19903
19911
19921
19930
19940
19950
19963
19976
19982
19990
20000
20010
20020
20031
20040
20051
20060
20070
20080
20090
20100
20110
20121
20130
20140
20154
20161
20170
20180
20190
20200
20210
Total41