*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19751
19760
19770
19781
19790
19800
19810
19821
19830
19841
19850
19860
19870
19880
19892
19902
19911
199231
19930
19940
19950
19962
19970
19982
19990
20001
20010
20021
20032
20041
20059
200639
200720
200824
200929
20108
201130
20129
20132
20145
20156
201610
201718
201811
20193
20206
20214
202215
202310
20244
Total312