*Excludes Observations that spanned multiple years

Pre 197012
19700
19710
19720
19730
19741
19750
19760
19770
19780
19790
19800
19811
19820
19831
19840
19850
19860
19870
19880
19890
19901
19911
19920
19930
19941
19951
19960
19970
19980
19990
20000
20010
20020
20030
20040
20050
20060
20072
200812
20091
20101
20110
20120
20130
20140
20150
20160
20170
Total35