Also, X is 9 times larger than Y and X is 9 times as large as Y are two different statements.
200% as large as 1 is 2.
200% larger than 1 is 3..
So 200% smaller is 3*2=6 smaller than 3, which is 3-6=-3
Which is why these kinds of statements usually don't make any sense at all. Usually something can't be more than 100% smaller, at which point it is completely gone.