*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19762
19771
19780
19790
19801
19810
19821
19835
19840
19851
19860
19870
19880
19890
19900
19911
19920
19930
19940
19950
19961
19970
19983
19996
20000
20016
20020
20030
20040
20050
20060
20070
20082
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total30