get_centenarian_data = function(){
    ##
    ## xpdf ../EBook/Applied_Linear_Models_with_R.pdf -z 200 349 &
    ##
    fn = '../../Data/centenarian.dat'
    DF = read.table(fn, header=FALSE, skip=0, nrows=13, col.names=c('Age_ALB', 'number_at_risk', 'Deaths', 'number_censored'), fill=TRUE)
    DF[is.na(DF)] = 0
    DF
}