*Excludes Observations that spanned multiple years

Pre 19700
19700
19713
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19851
19861
198773
198861
19899
19904
1991130
199261
1993118
199427
1995133
1996144
1997108
19988
199921
20000
200139
200212
200312
20045
20053
20060
20076
20089
200913
201015
20114
20126
20132
20144
20153
20169
20172
20183
20190
20205
202118
20223
20231
20242
Total1078