*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19883
19894
19903
199129
19923
199328
19946
19951
19961
199717
199812
19993
20001
200124
20025
20030
20044
20056
20061
20072
20085
20091
20101
20112
20120
20130
20140
20150
20161
20170
Total163