*Excludes Observations that spanned multiple years

Pre 19700
19700
19711
19721
19730
19740
19750
19760
19770
19780
19790
19800
19811
19820
19830
19840
19850
19860
19870
19880
19895
19901
19912
19921
19930
19944
19950
19960
19970
19980
19990
20000
20011
20020
20030
20040
200512
20060
20070
20080
20090
20100
20110
20120
20131
20141
20151
20162
20178
20180
Total42