*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19755
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19901
19913
19927
19930
19940
19952
19960
19970
19981
19993
20003
20016
20024
200312
20049
20054
20063
20073
20081
20090
20100
20111
20120
20130
20140
20150
20160
20170
Total68