*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19841
19851
19860
19872
19884
19892
19900
19910
199211
19932
19944
19950
199613
19972
19985
19992
20000
20010
20020
20031
20043
20052
20060
20070
20080
20092
20100
20110
20120
20130
20141
20150
20160
20170
Total59