You would need to evaluate how valuable and important you are to the company. Knowing your stand in the company, you can roughly set an expected increament range.

My minimum increment would be around 20%, the highest being 30%.

But then again, I know where my value is, and how important I am to the organisation. It's about demand of supply. Guess I capitalised on that.

That's when you need to consider other options. If you know your real worth but HR is under-cutting you, then perhaps you might prefer to move on to another organisation where your skills and capabilities will be well appreciated.