*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19851
19860
19870
19880
19891
19900
19911
19920
19937
19943
19952
19960
19971
19981
19990
20004
20010
20020
20035
20040
20051
20060
20070
20080
20090
20102
20115
20120
20130
20141
20150
20160
20170
Total35