*Excludes Observations that spanned multiple years

Pre 19709
19701
19711
19720
19730
19740
19750
19760
19770
19781
19791
19804
19810
19820
19830
19840
19852
19861
19870
19883
19891
19900
19911
19922
19930
19940
19951
19960
19971
19981
19990
20001
20010
20022
20032
20043
200511
20064
20074
200821
200919
201016
20118
20125
20134
20142
20153
20163
20170
Total138