*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19864
19870
19888
19890
19900
19910
19922
19933
19941
199513
19960
199721
19980
19992
20007
20010
20024
20032
20040
20051
20060
20070
20081
20090
201027
201152
20122
20134
20140
20150
20161
20170
Total156