*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19821
19830
19845
19851
19862
19870
19881
198930
19902
19914
19928
19930
19949
19955
19966
19975
19981
19990
20000
20012
20020
20034
20041
20053
200610
20075
20081
20092
20101
20116
20120
20130
20140
20150
20160
20170
20180
Total115