*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
19880
19890
19900
19911
19921
19930
19942
19951
19962
199725
199812
19990
20006
20011
20020
20035
20041
20053
20060
20070
20082
20090
20103
20113
20120
20130
20140
20150
20160
20170
Total68