*Excludes Observations that spanned multiple years

Pre 19705
19700
19710
19720
19730
19741
19750
19761
19770
19781
19791
19801
19810
19820
19830
19841
19850
19860
19871
19880
19890
19900
19910
19920
19930
19940
19950
19960
19970
19980
19991
20001
20010
20021
20030
20040
20050
20060
20070
20080
20091
20101
20110
20120
20130
20142
20150
20160
20170
Total19