*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19781
19790
19800
19811
19820
19832
19840
19850
19860
19877
198821
19891
19904
19919
199211
199310
19943
19951
19961
19978
19981
19992
20009
20010
20020
20030
20040
20051
20061
20071
20080
20094
20100
20111
20120
20130
20140
20150
20160
20170
Total100