*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
19880
19890
19902
19914
19925
19933
19941
19951
19963
19975
19980
19991
20002
20015
20021
20037
20045
20051
200612
20074
20089
200910
20108
20111
20126
20134
20140
20150
20160
20170
Total100