*Excludes Observations that spanned multiple years

Pre 19705
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19871
19881
19890
19900
199112
19920
19932
19940
19952
19960
19970
19981
19991
20004
20010
20020
20030
20040
20056
20062
20070
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total37