*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19803
19810
19820
19830
19840
19850
19860
19870
19883
19890
19900
19910
19921
19938
19940
19951
19961
19976
19987
19992
20000
20013
20020
20035
20042
20055
20060
20071
20082
20090
20100
20111
20120
20130
20140
20150
20160
20170
Total51