*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19841
19852
19863
19879
19880
19890
19902
19914
19923
19932
19940
19952
19960
19970
19980
19995
20000
20010
20020
20030
20040
20051
20060
20070
20080
20091
20100
20110
20123
20130
20140
20150
20160
20170
Total38