*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19802
19811
19820
19832
19840
19850
19869
19872
19884
19892
19901
19911
19923
19934
19944
19953
19961
19970
19980
19992
20001
20019
20024
20030
200430
20050
20064
20070
200814
20090
201024
201120
20120
20130
20141
20150
20163
20170
Total151