*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19882
19890
19900
19910
19922
19930
19940
19955
19960
19971
19980
1999110
200048
20017
200211
20031
20040
20050
20061
20070
20080
20091
20100
20112
20120
20131
20140
20151
20161
20171
20180
Total195