*Excludes Observations that spanned multiple years

Pre 19705
19700
19710
19720
19730
19740
19751
19760
19770
19780
19791
19800
19811
19820
19830
19841
19850
19860
19870
19880
19890
19900
19910
19920
19930
19941
19950
19962
19970
19980
19990
20001
20011
20020
20030
20040
20053
20060
20070
20082
20090
20101
20110
20121
20131
20140
20151
20160
20170
20180
20190
20200
Total23