*Excludes Observations that spanned multiple years

Pre 19702
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19840
19850
19868
19877
19889
19894
19902
199119
199213
19936
19947
199511
199610
19979
19983
19990
20002
20013
20020
20032
20041
20051
20060
20070
200810
20091
201016
201111
20120
20130
20140
20150
20163
20170
Total161