*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
19871
19882
19890
19901
19910
19920
19934
19941
19950
19963
19977
199810
199910
200010
20019
20027
200310
20047
20055
200623
200716
200816
200915
201041
201135
201219
201316
201416
201517
20164
20170
20180
Total305