The petition shall set forth the plan for refunding and compromising the indebtedness and shall further recite what percentage in amount of the holders of the evidences of indebtedness to be refunded or retired have filed their written consent to the proposed plan, which percentage shall not be less than 90 percent, and shall further set forth what steps have been taken to obtain the consent of all nonconsenting holders of the evidences of indebtedness. The petition shall also state the name and place of residence of all of the holders of the evidences of indebtedness who are known to the district, and shall show that diligent efforts have been made to ascertain the names and residences of all the holders.