20 31-32 21 33-34 22 35-36 23 23^1/2 24 25 26 27 27^1/2 28 28^1/2 29 29^1/2 30 18 19 21-22 22-23 23-24 25-26 27-28 29-30 31 31^1/2 32 32^1/2 33 34 34^1/2 35 35^1/2 36 36^1/2 36^2/3 37 37^1/3 37^1/2 38 38^1/2 38^2/3 39 39^1/3 40