A sample of a metal oxide has formula ${\mathrm{M}}_{0.83}{\mathrm{O}}_{1.00}$. The metal $\mathrm{M}$ can exist in two oxidation states $+2$ and $+3$. In the sample of ${\mathrm{M}}_{0.83}{\mathrm{O}}_{1.00}$, the percentage of metal ions existing in $+2$ oxidation state is $\%$. (nearest integer)