*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19861
19877
19880
19899
19901
19911
199220
199313
19941
19958
19960
19972
19982
19993
20001
20011
20021
20031
20047
200536
20061
20071
20082
20092
20100
20110
20120
20130
20140
20153
20161
20170
Total125