*Excludes Observations that spanned multiple years

Pre 1970151
19705
19711
19725
19731
19740
19755
19763
19773
197810
19797
198014
19812
19823
19831
19841
19853
19860
19870
19880
19890
19903
19911
199218
199311
19942
19953
19963
19975
19983
19994
20000
20010
20024
20030
20040
20052
200612
20072
20088
200920
201078
201113
20124
20133
20140
20151
20160
20170
20180
20190
20200
20210
Total415