Uranium in ore exist in $+4$ oxidation states which during sulfuric acid leching is oxidized to $+6$ oxidation state as uranyl ion $(U{O}_2^{+2})$ and dissolved in solution. This uranyl ion combines with sulfate ion in the solution to form uranyl sulfate anions. The figure below shows the Eh$-pH$ diagram for uranium$-$sulfate system. Using the figure determine;

What two forms of uranyl sulfate anion exist in the system?

Under what Eh and pH range do these two forms exist? Eh can be approximate value.