To be honest saying there is a ban rate for anything is stupid. I have botted 200 hours straight at yews in catherby, but never had a problem. honestly, make good breaks, run a good script, and every so often try and talk with someone, and you wont get banned. Also if you have been using the account for regular use, dont try and bot. the small change in your routine will throw a flag.
One of the best things i think is the routine. If you want to bot 99 runecrafting at nats, make sure you bot like 5 hours a day, same time frame, same breaks, ect. That way it looks more legit. If you put you are 18, then JaGex will think you have school, dont try and bot during these hours. There are small things that will change wether or not you get banned, and you will learn them slowly. Just make sure to bot SMART.