Consider the following four risky assets:

An investor currently has $50\%$ of her money in "Australia" and $50\%$ of her money in "Belgium". However, she wants to create a portfolio with the same expected return as her current portfolio, but with the lowest variance possible using all $4$ assets, but not the risk$-$free asset. What percent of her money should she put into the "Australia" asset to achieve this goal?

Answer in decimal format, rounded to $4$ decimal places. For example, if your answer is $12\mathrm{.}124\%,$ enter $"0\mathrm{.}1212".$ If your answer is $12\mathrm{.}188\%,$ enter $"0\mathrm{.}1219".$