*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19781
19792
19800
19811
19821
19833
19843
19856
19861
19874
19886
19897
19901
19916
19924
19932
19949
199510
199616
199739
199844
199935
200011
200137
200267
200370
200434
200532
200642
200755
200824
200947
201055
201155
201248
201326
201431
201533
20161
20170
20180
Total869