Based on data from $1940$ to $2000,$ the average yearly Social Security benefits for retired individuals in the United States has been modeled by S$($t$)=0\mathrm{.}348$t$^(2)-5\mathrm{.}506$t $+35\mathrm{.}13$ in thousands of dollars, where t is time in years since the start of $1940(0<$ t$<60).$