*Excludes Observations that spanned multiple years

Pre 19700
19701
19710
19720
19730
19740
19750
19760
19770
19780
19791
19800
19810
19820
19830
19840
19852
19866
19871
198820
19890
19900
19915
19922
19930
199410
19951
19960
19976
19982
19996
20001
20010
20024
20033
20040
20051
20060
20070
20087
20090
201011
20117
20120
20130
20140
20150
20160
20170
Total97