*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
19883
19890
19900
19914
19921
19930
19941
19952
19961
19970
19983
19990
20002
20010
20020
20030
200430
20050
20065
20070
20080
20091
20100
20111
20120
20130
20140
20150
20160
20171
Total55