*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19881
19890
19900
19911
19920
19930
19940
19951
19960
19970
19984
19990
20001
20010
20020
20031
20040
20050
20060
20070
20080
20091
20102
20111
20121
20131
20140
20150
20161
20170
Total16