condition mean min max ZT0-3 7.008495 6.702675 7.314315 ZT4-7 17.177 17.177 17.177 ZT8-11 19.55705 19.55705 19.55705 ZT12-15 0 0 0 ZT16-19 7.195695 7.195695 7.195695 ZT20-23 13.15765 13.15765 13.15765