*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19781
19790
19800
19810
19820
19830
19840
19850
19863
19875
198828
19892
19905
19914
19921
19933
19943
199527
199619
199711
199821
199913
20003
20010
20020
20033
20042
200510
20061
20071
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total166