I'm with crippler..focus less on new programs and more on getting the word out to your target audience about what you can offer. Find ways to make what you do attractive to adults and you'll get more of them.
that being said, at the school I train at...we suffer from low adult attendace as well. However, the owner periodically does a family trains free month. Any parent, sibling, etc of a currently training student can train for free for a month. That often brings in a whole cadre of adults (parents who are apprehensive about trianing but interested after watching their kids)...many stay for quite awhile.
Mind you, this only targets people who are already in the door. Advertising will be what brings in new blood. (so to speak)
Peace,
Erik