*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19813
19820
19830
19841
19850
19865
19872
19880
19890
19901
199110
19923
19937
19944
19950
19960
19970
19980
19991
20003
20010
20020
20031
20040
20050
20060
20070
20080
20091
20100
20110
20120
20131
20140
20150
20160
20170
20181
20190
Total44