Sucrose hydrolyses in acid solution into glucose and fructose following first order rate law with a half-life of 3.33 h at 25$^\circ$C. After 9 h, the fraction of sucrose remaining is f. The value of ${\log _{10}}\left( {{1 \over f}} \right)$ is ________ $\times$ 10^$-$2. (Rounded off to the nearest integer)
[Assume : ln 10 = 2.303, ln 2 = 0.693]