the growth factor is simply the same amount, but in decimal format, so what is 5.1% of anything?
[tex]\begin{array}{|c|ll} \cline{1-1} \textit{a\% of b}\\ \cline{1-1} \\ \left( \cfrac{a}{100} \right)\cdot b \\\\ \cline{1-1} \end{array}~\hspace{5em}\stackrel{\textit{5.1\% of anything}}{\left( \cfrac{5.1}{100} \right)anything}\implies 0.051(anything)[/tex]
so the growth factor is simply the decimal format of 0.051.