*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
19870
19880
19894
19906
19914
19923
19935
19942
19959
199616
19975
19984
19991
20001
20011
20021
20034
20040
20051
20061
20070
20082
20090
20100
20110
20120
20130
20140
20150
20163
20171
20180
Total74