*Excludes Observations that spanned multiple years

Pre 19707
19701
19711
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19840
19850
19861
19870
19880
19890
19900
19911
19920
19930
19940
19950
19960
19970
19981
199937
200013
20018
2002112
20031
20041
20055
20066
200714
20083
200946
2010116
20111
20129
20137
201413
20158
201617
20173
20180
Total433