*Excludes Observations that spanned multiple years

Pre 197097
19700
19710
19720
19731
19743
19755
19761
19770
19781
19790
19801
19810
19820
19830
19840
19854
19860
19870
19881
19893
19900
19910
19920
19930
19941
19950
19961
19976
19980
19992
20002
20016
20023
20033
20040
20050
200619
20070
20086
20097
201012
20117
201221
201354
20145
20158
20160
20170
Total280