The script is a nice feature. It tells you how many rejections it would take to bring you down to 99% and 95%. In your case, it would take 374 rejections to bring you down to 95%. So you have room. Just gives you an idea. You want to try not to get too many rejections so you can qualify for more HITs. Most requirements have 95% or greater so you want to keep it above 95% approval rate.