condition mean min max ZT0-3 13.65905 13.32085 13.99725 ZT4-7 20.03415 20.03415 20.03415 ZT8-11 25.4792 25.4792 25.4792 ZT12-15 0 0 0 ZT16-19 14.6562 14.6562 14.6562 ZT20-23 14.5333 14.5333 14.5333