Having played a ton of ap's over a decade ago, I would say back then the average number was even lower. There were just a lot more people worth 0-1 charges. I'd guess it was closer to .5-.6 per kill. To get your first control it would often take 50ish kills. However, that was back when you could get your controls outside of hero range and most ap's sat in the 36-40 range for a long time.