*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19811
19821
19831
19840
19850
19860
19870
19880
19890
19901
19910
19920
19930
19940
19951
19960
19970
19980
19990
20001
20011
20021
20036
20047
20051
200612
20077
20080
20091
20104
20110
201211
201318
201441
201533
20168
20170
Total158