thats  only on the top wing, theory was explained to me that having a little negative incidence on the top is way better than having any positive incedence, and the washer was meant to err on the side of caution. as for the stab &  bottom wing they are at 0.
actually with an inceidence meter it's not bad, cause you want to compare the wing tips to the fuse side of the wings. also helps to have your radio and rcvr on so that the servos hold the center position, worked for me anyways