*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19729
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19876
198822
19891
199013
19917
19923
19935
19940
19951
19960
19970
19980
19994
20008
20010
20022
20030
20040
20050
20060
20070
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
20181
20190
Total82