*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19751
19760
19771
19780
19790
19800
19810
19822
19830
19840
19850
19860
19870
19881
19890
19900
19910
19921
19931
19944
19950
19964
19972
19980
19990
20008
20010
20020
20030
20040
20050
20061
20070
20081
20090
20101
20110
20120
20131
20140
20150
20160
20171
201813
20191
20200
Total44