Mr. E, a petroleum engineer, earns an $83,000 annual salary, while Mrs. E, a homemaker, has no earned income. Under current law, the couple pays 20 percent in state and federal income tax. Because of recent tax law changes, the couple's future tax rate will increase to 28 percent. If Mrs. E decides to take a part-time job because of the rate increase, how much income must she earn to maintain the couple's after-tax disposable income?