Well it depends on alot of things really. The Environment, the amount of light, the cultivar and how mature the plant is.
As a roundabout figure, a mature plant will produce between 3 and 7 leaves per rhizome crown (any more you actually have more than one rhizome fused together). Each leaf will grow anywhere up to about 5 inches in length.
Trap sizes vary hugely depending on cultivar. Typical traps will grow to a maximum of around 1 inch across and large trapped varieties such as Slack’s Giant or any of the larger ‘G’ clones will grow to a maximum of 2 inches across.