bit like asking how long is a piece of string, lol! Depends entirely on the conditions - outside during summer, with sufficient water and warm conditions with long daylight hours, growth rate will be rapid. Inside, this time of year, much slower. And that's all I can tell you I'm afraid.

It does depend on the variety, but I bought a dwarf variety a couple of years ago and kept it in a pot outside on the patio. It had 1 open leaf in May, 3 by the end of June and 6 by September. Unfortunately I failed to overwinter it properly and lost it.