That's not how this kind of thing works, and it depends on where it starts. If it's 1% of children attempting suicide, which would be a huge amount, a 10% increase is 1.1%, and then for the next year a 10% increase makes it 1.21%, and then 1.33%. This is why when something increases your risk of something by say, 50%, it might mean absolutely nothing if the initial odds are 1 in a billion. 1.5 in a billion isn't really any more likely.