Des Moines is the No. 9-ranked major market in the BizJournals.com On Numbers Economic Index for April. That's up one spot from March. The index measures the vitality of 102 markets with populations of more than 500,000, using an 18-part formula assessing private-sector job growth, unemployment, personal earnings and other factors. Austin, Texas, was the No. 1 market on the list in April, followed by Provo, Utah, Dallas-Fort Worth, Houston and Oklahoma City.