plot(pd$debratemf_~pd$tfr_,
   xlim=c(1,2.3), ylim=c(0,105),
   pch=pd$char, col=pd$color, cex=.5, bty="l",
   main="Period TFR and Mortgage Debt Ratio",
   xlab="Period Total Fertility Rate (TFR)",
   ylab="Total Outstanding Residential Loans (% GDP)")