*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
19873
19880
19891
19900
19910
19928
199311
19942
199550
19960
199723
199817
19991
20002
20014
20021
20030
20041
20055
20060
20072
20082
20091
20100
20110
20120
20130
20140
20153
201611
20170
Total148