*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19852
19860
19870
19880
19890
19900
19910
19920
19930
19944
19954
19960
19978
19980
199944
20000
20012
2002133
20039
200467
200571
2006138
2007196
200888
200946
2010169
201164
201262
20133
20140
20150
20160
20170
Total1110