Hey Karl,
The actual number is something I have never measured. The important thing is that the jet retracts fully (in or up) until it contacts the adjustment nut when the choke is in fully. If it does not go up fully, then your engine will run rich (rough idle with black smoke out the tail pipe), and you will not get any adjustment from the nut to fix it.
With the jet fully up, you connect the choke cable with the knob fully in. The amount of jet movement is now set by the linkage geometry, and you don't have any control over it unless something is bent or damaged.