How old is David Phelps?

If there are any David Phelps fans here, has anyone been to a concert or watched a DVD where David mentioned how old he is? I know he's married with four precious children, but I have yet to know how old he is. He has to be between 20 and 40 for sure. He joined the Gaither Vocal Band in 1996 and left in 2004, and has now returned for the Reunited Tour. Thanks in advance!!