How many are disproportionation reactions?

$\left(\mathrm{i}\right) 2{\mathrm{Cu}}^{+}⟶{\mathrm{Cu}}^{2+}+{\mathrm{Cu}}^0$

$\left(ii\right) 3{\mathrm{MnO}}_4^{2-}+4{\mathrm{H}}^{+}⟶2{\mathrm{MnO}}_4^{-}+{\mathrm{MnO}}_2+2{\mathrm{H}}_2\mathrm{O}$

$\left(iii\right) 2{\mathrm{KMnO}}_4\stackrel{\Delta }{⟶}{\mathrm{K}}_2{\mathrm{MnO}}_4+{\mathrm{MnO}}_2+{\mathrm{O}}_2$

$\left(\mathrm{iv}\right) 2{\mathrm{MnO}}_4^{-}+3{\mathrm{Mn}}^{2+}+2{\mathrm{H}}_2\mathrm{O}⟶5{\mathrm{MnO}}_2+4{\mathrm{H}}^{+}$

The redox reaction in which one element of reactants undergo oxidation as well as reduction is called disproportion redox reactions.
$\mathit{3}{\mathit{M}\mathit{n}\mathit{O}}_{\mathit{4}}^{\mathit{2}\mathit{-}}\mathit{+}\mathit{4}{H}^{\mathit{+}}\stackrel{\mathit{\Delta }}{\mathit{⟶}}\mathit{2}{\mathit{M}\mathit{n}\mathit{O}}_{\mathit{4}}^{\mathit{-}}\mathit{+}{\mathit{M}\mathit{n}\mathit{O}}_{\mathit{2}}\mathit{+}\mathit{2}{H}_{\mathit{2}}O$ is called disproportion redox reaction.
(1) $\mathit{2}{\mathit{C}\mathit{u}}^{\mathit{+}}\mathit{\to }{\mathit{C}\mathit{u}}^{\mathit{+}\mathit{2}}\mathit{+}{\mathit{C}\mathit{u}}^{\mathit{\circ }}\mathit{:}$disproportion redox reaction
(3) $\mathit{2}{\mathit{M}\mathit{n}\mathit{O}}_{\mathit{4}}\stackrel{\mathit{\Delta }}{\mathit{⟶}}{K}_{\mathit{2}}{\mathit{M}\mathit{n}\mathit{O}}_{\mathit{4}}\mathit{+}{\mathit{M}\mathit{n}\mathit{O}}_{\mathit{2}}\mathit{+}{O}_{\mathit{2}}$ this reaction is not possible because reactant (MnO4) does not exist.
(4) $\mathit{2}{\mathit{M}\mathit{n}\mathit{O}}_{\mathit{4}}^{\mathit{-}}\mathit{+}\mathit{3}{\mathit{M}\mathit{n}}^{\mathit{2}\mathit{+}}\mathit{+}\mathit{2}{H}_{\mathit{2}}O\mathit{\to }\mathit{5}{\mathit{M}\mathit{n}\mathit{O}}_{\mathit{2}}\mathit{+}\mathit{2}{H}^{\mathit{+}}$ comproportionation redox reactions.