Issuance of new securities backed by multifamily mortgages increased dramatically last year, reversing a sharp decline that took place back in 2000, according to a new Inside MBS & ABS analysis of the sector. Total multifamily MBS production climbed from $20.70 billion in 2000 to $30.13 billion last year, an increase of 45.5 percent. That was enough to beat the $29.54 billion