*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
197253
197325
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
198643
198743
198841
198918
199016
199118
19922
19932
19941
19956
19962
199718
19988
1999119
2000170
2001109
200226
20034
20040
20053
20063
20078
20089
20094
20104
20114
201212
20139
201413
201511
201624
201716
20180
Total844