*Excludes Observations that spanned multiple years

Pre 19700
19700
19711
19720
19730
19741
19750
19760
19770
19780
19790
19800
19810
19820
19831
19844
19850
19860
19870
19887
19894
19907
19919
19926
19933
19944
199518
199610
199712
199813
19993
20000
200110
20022
20037
20043
20056
20062
20071
20081
20091
20100
20110
20120
20130
20140
20151
20161
20170
Total138