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