*Excludes Observations that spanned multiple years

Pre 19700
19700
19711
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19842
198534
198640
198753
1988332
198910
19903
199179
199219
199325
19949
199529
199619
199721
19980
199957
200066
200121
200213
200313
20045
20057
20066
20079
20088
20096
20107
20114
201210
20138
20147
201510
20168
201710
20181
20194
20203
20214
20223
20230
20240
Total966