N1, N2, N3, N4, N5, N6, and N7  earn different incomes. N3 earns more income than N1 but less than N5. N6 earns less income than only two people. N4 earns the lowest income . N2 has less income than N1. N5 earns the highest income. N7 earns more than N6. Who earns the Second highest income?