*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19876
19886
19893
19900
199116
19925
199318
19945
19951
19967
19975
19980
19992
20000
20011
20020
20031
20040
20050
20060
20077
20087
20090
201019
201122
20120
20130
20142
20152
20160
20170
Total135