*Excludes Observations that spanned multiple years

Pre 19700
19700
19711
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19840
19850
19863
19870
19885
19890
19909
19915
199210
199311
19946
199537
19961
199717
19983
19996
20001
20014
20022
20039
20049
200517
20061
20070
200813
20090
201022
201141
20121
20131
20141
20155
201613
20170
Total255