How old is my Free spirit Bike?

Its a standard (no handlebar brakes. You have to pedal backwards) One gear. Plain simple bike. I have read many other topics similar to this one saying how I can tell how old it is by the serial number but i cant find it!!! There are several numbers in the handlebar area but none of them meet the discriptions to tell the age. Im really confuzed. Is my bike special because there is only one gear and no brakes on the handel bar because when I search for it that is all I see.