*Excludes Observations that spanned multiple years

Pre 197086
19709
19714
19725
19733
19742
19752
19760
19773
19781
197911
198012
19816
19822
19839
19849
19855
19862
19871
19884
19894
19902
19913
19923
199321
19949
199515
199613
199711
199810
199916
200019
200112
200215
200311
20049
200516
200612
20078
200819
200911
201017
201120
201212
201310
20147
20159
20165
20174
Total499