condition mean min max ZT0-3 10.090448 10.090448 10.090448 ZT4-7 12.366339 12.366339 12.366339 ZT8-11 15.0071325 15.0071325 15.0071325 ZT12-15 16.274097 16.274097 16.274097 ZT16-19 23.284270999999997 23.284270999999997 23.284270999999997 ZT20-23 36.9121615 36.9121615 36.9121615