You got several simple accurate answers, some explaining the reasoning behind the answers, to which you decided that wasn't a good enough answer, even though in the next post you gave examples confirming yourself there isn't a standard fixed rate that works in all situations. Your replys in this thread have the tone of having a bit of an attitude about you, although going by the unusual phrasing and grammar I'm starting to wonder if you struggle a bit with the english language and you don't really mean to come across twattish maybe it's just a language barrier?