*Excludes Observations that spanned multiple years

Pre 19708
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19803
19810
19820
19830
19841
19850
19863
19870
19881
19890
19900
19910
19928
19930
19941
19950
19960
199717
19981
19990
20000
20011
200210
20030
200415
20050
20060
20070
20080
20091
20100
20114
20121
20132
20140
20151
20160
20172
20180
Total80