*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19841
19850
19860
19870
198818
19890
19900
199141
1992107
19939
19940
19950
19960
19970
19981
19990
20006
20010
20020
20034
20043
20050
20060
20071
20080
20091
20101
20112
20121
20130
20142
20151
20161
20171
20181
Total203