*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19840
19856
19862
19875
19880
19896
19900
19910
19920
19930
19941
19950
19960
19971
19980
19991
20000
20014
20020
20030
200433
20050
20060
20070
20087
20090
20104
20114
20120
20133
20140
20150
20160
20170
Total78