*Excludes Observations that spanned multiple years

Pre 197018
19700
19710
19720
19730
19740
19750
19760
19770
197815
19790
19800
19810
19820
19835
19840
19850
19860
19872
198846
19890
19901
199111
199211
199310
19941
19958
19964
19970
19982
19990
20001
20012
20020
20034
20043
20058
20061
20070
20081
20091
20101
20111
20120
20131
20140
20150
20160
20170
Total158