*Excludes Observations that spanned multiple years

Pre 19700
19700
19711
19720
19730
19740
19750
19760
19770
19780
19790
19800
19812
19820
19830
19840
19850
19860
19870
19880
19891
19904
19911
19921
19930
19940
19951
19962
19970
19980
19990
20000
20010
20020
200343
20040
20056
20065
20070
20084
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total71