*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19721
19731
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19888
19890
199028
19913
19922
19931
19940
19950
19960
19972
19983
19990
20000
20013
20020
20031
20040
20051
20061
20071
20080
20090
20100
20110
20120
20131
20140
20150
20160
20170
20180
20190
Total57