Passenger numbers at Des Moines International Airport were up 8.4 percent in April compared with the same month a year ago, according to figures released by the airport today. A total of 171,708 passengers came through Des Moines during the month, up from 158,430 in April 2012. That marks the 33rd straight month that the airport has reported a year-over-year increase in passenger activity. For the year, a total of 693,194 passengers have enplaned or deplaned at the airport, up 8.3 percent over 2012. Cargo activity for April was down 6.6 percent from a year ago, and for the year is down 1.4 percent.