When we talk about "1000 percent", we mean something has gotten a lot bigger. Imagine you have a toy car that can only fit one little toy person inside. If you add 10 more toy people to the car, that's a big increase - it's 1000 percent more people than before!
Similarly, if you have a little bit of money and you earn ten times as much money, that's also a 1000 percent increase. It means your wealth has grown a lot!
So when we say "1000 percent", we're just talking about something that's gotten much, much bigger than before.