*Excludes Observations that spanned multiple years

Pre 19705
19701
19710
19721
19730
19741
19750
19763
19770
19780
19791
19801
19810
19822
19838
19841
19850
198624
198710
19884
198939
19908
19911
199222
199328
199429
199515
199636
199710
199821
19998
20001
20012
20021
20031
20042
2005112
200617
20075
20082
20096
20102
20118
20127
20136
20143
20153
20163
20173
Total463