*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19848
19850
19861
19874
19882
19894
19900
19912
19921
19934
19940
19950
19960
19971
19980
19995
200012
20014
20023
20030
20040
20051
20060
20071
20080
20091
20100
20110
20120
20130
20140
20150
20161
20170
20181
Total57