*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19781
19790
19801
19811
19820
19831
19840
19851
19861
19870
19883
19890
19900
19910
19925
19937
19949
19951
19962
19971
19982
19990
20000
20010
20021
20033
20040
20050
20062
20074
20082
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total48