*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19771
19782
19790
19800
19810
19820
19831
19840
19850
19863
19874
198829
19899
19907
199125
199212
199315
19941
19953
19968
19972
19987
19995
20003
20013
20020
20036
20040
20054
20061
20072
20088
20095
20102
20114
20121
20132
20144
20151
20167
20171
20180
20190
Total188