19991218
       19811230      71.2
       19851201      77.4
       19851202      73.2
       19851205      73.4
       19851206      72.0
       19851208      75.8
       19871224      79.6
       19881204      73.3
       19881205      71.1
       19881206      72.7
       19891223      76.7
       19891224      72.5
       19901231      79.5
       19911202      71.6
       19911203      84.7
       19911204      72.2
       19921213      83.7
       19921216      71.8
       19951206      77.5
       19951207      84.5
       19991216      70.3
       19991217      83.6
       19991218     100.0
       19991219      74.4
       19991220      73.2
       20001207      74.4
       20011202      80.5
       20021218      73.0
       20021227      75.3
       20021228      71.5
       20081201      74.1