*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19840
19853
19860
198717
19884
19893
19901
19910
19923
19932
19944
199514
19960
19974
19981
19992
20001
20014
20020
20032
20040
20055
20064
200714
200811
20099
20109
20118
20120
20130
20142
201523
201640
20170
20180
Total191