How many grams per square meter is an ounce per square yard

How many grams per square meter is an ounce per square yard

1 ounce ounces = 16 drams = 28.35 grams
1 yard yard = 3 feet = 0.9144 metre
1 square yard = 0.83612736 square meters
So ounces per square yard = 28.35/0.83612736 = 33.906317812636 grams per square meter
But this composite unit doesn't seem to make much sense. Is it pressure? Pressure should be in mechanical units instead of weight units