*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19851
19860
19878
19880
19896
19905
19919
199212
19932
19944
199518
19965
199725
199816
19997
200012
20015
20021
20033
20043
20053
20060
20071
20080
20091
20100
20110
20120
20130
20140
20150
20160
20170
Total147