*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19726
19734
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
198514
19861
19871
19888
198915
199016
199130
1992109
19930
19940
19951
19960
19970
19980
199918
20009
20019
20022
20033
200433
20053
20061
20073
20082
20094
20106
20112
20124
20134
20147
20156
20165
20173
20181
Total330