*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19821
19830
19840
19850
19862
19870
19881
19890
19901
19912
199216
19930
19940
19954
19963
19971
19980
19991
20000
20010
20020
20030
20041
20050
200610
20075
20080
20091
20101
20113
20120
20130
20140
20150
20160
20170
Total53