*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19834
19840
19850
19863
19873
19887
19896
19909
19913
199210
199317
19946
19955
19962
199712
199815
199917
20002
200112
20021
20039
200452
20052
20063
200714
20087
20094
20105
20112
20126
201313
20148
201514
20168
20173
Total284