animation speed in mdl

hi how can i make my animation speed slower? i want to double the time
via mdl editing

// MDLFile version Jun 27 2002 20:34:57
// Exported on Mon Jul 12 15:29:39 2004
Version {
FormatVersion 800,
}
Model "buildmodel" {
NumGeosets 2,
NumBones 7,
NumParticleEmitters2 1,
BlendTime 150,
MinimumExtent { -171.555, -222.284, -159.598 },
MaximumExtent { 247.731, 246.764, 244.104 },
BoundsRadius 272.841,
}
Sequences 1 {
Anim "Birth" {
Interval { 1667, 61667 },
NonLooping,
}
}