Since you have 500 followers then up to 10,000 you are at the solution 2.3 * x^2 = 10,000 -> x^2 = 4,347 -> x = sqrt(4,347) which is approximately 65.9, and since you have 500, you are at the solution 2.3 * x^2 = 500 -> x^2 = 217 -> x = sqrt(217), which is approximately 14.7. Now let's calculate 14.7 * 100/65.9 = 22.3.
You are 22.3% up to XarryBerry. Not a bad result!