*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19821
19830
19840
19850
198631
19870
19880
19893
19900
19910
19921
19930
19940
19953
19960
19970
19981
19996
20001
20015
20021
20031
20040
20058
20064
20073
20082
20091
20103
20112
20120
20130
20140
20150
20165
20170
Total82