*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19865
19870
19885
19893
19907
19914
19927
19936
19942
199513
199611
199716
199812
19995
20007
20013
20028
20035
20042
20053
20062
20070
20085
20090
20100
20111
20120
20130
20140
20150
20162
20170
Total134