*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19881
19890
19901
19913
19922
19930
19940
19954
19960
19970
19980
19990
20000
20012
20021
20030
20040
20050
20060
20070
20084
20090
201010
201117
20120
20130
20142
20150
20160
20170
Total47