*Excludes Observations that spanned multiple years

Pre 19700
19701
19710
19721
19730
19740
19750
19760
19770
19780
19790
19802
19810
19820
19830
19840
19850
19861
19870
19889
198923
199020
199132
199231
199347
19947
199543
199610
199741
199832
19996
200021
20018
200216
20034
200410
200512
20062
200710
200811
20092
20109
20117
20120
20130
20140
20150
20163
20170
Total421