*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19782
19790
19801
19810
19820
19830
19840
19852
19860
19871
19883
19892
19905
19911
19927
19932
19946
19953
19962
19970
19984
19991
20003
20010
20020
20032
20042
20050
20060
20070
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total49