*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19821
19831
19840
19850
19860
19870
19880
19890
19900
19911
19920
19933
19940
19951
19961
19970
19981
19990
20006
20010
20020
20030
20040
20050
20060
20070
20080
20090
20106
201119
20122
20130
20142
20151
20160
20170
Total45