*Excludes Observations that spanned multiple years

Pre 19701
19700
19711
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19821
19830
19841
19851
19860
19872
198816
19891
19906
19918
199219
199315
19941
19951
19961
19971
19980
19991
20000
20010
20020
20032
20046
20051
20063
20079
20089
20090
20100
20110
20120
20130
20141
20150
20169
20170
Total117