*Excludes Observations that spanned multiple years

Pre 1970178
19706
19711
19721
19730
19743
19751
19763
19774
19781
19793
198017
19812
19821
19831
19841
19851
19861
19870
19880
19890
19901
19910
19921
19933
19945
19955
19964
19973
19984
19993
20002
20014
20025
200319
200426
200510
200627
20075
200825
200930
201039
20119
201212
201310
20147
201511
20163
20170
Total498