*Excludes Observations that spanned multiple years

Pre 197012
19702
19710
19720
19730
19741
19754
19760
19770
19781
19790
19802
19810
19824
19831
19841
19851
19860
19870
19880
19894
19902
19913
19920
19930
19942
19952
19961
19970
19981
19990
20003
20018
20020
20030
20040
20050
20060
20071
20085
20091
20100
20111
20121
20131
20140
20150
20161
20173
20180
20192
20201
20212
20221
20235
20240
Total80