With the chord line of the airfoil horizontal, a cambered section will have lift at this "zero incidence".
Typically the zero life line will be at a negative alpha, (angle of attack, not angle of incidence).
The NACA 2*** family shows a consistency for the camber, zero lift changing more negatively as the Re increases.
Re is a factor based on chord and airspeed. The more of either, the better the profile performs.
http://www.nasg.com/afdb/index-e.phtml