*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19791
19800
19810
19820
19830
19840
19851
19862
19870
19880
19892
19904
19914
19922
19932
19947
199515
19965
19974
199812
19997
20000
20010
20020
20030
20042
20050
20061
20072
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total73