*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19861
19870
19880
19895
199014
199124
199219
199310
19946
19953
199610
199713
19983
19990
20001
20013
20021
20033
20044
20051
20061
20073
20081
20090
20100
20112
20120
20130
20140
20150
20161
20170
Total129