condition mean min max ZT0-3 17.14985 17.14985 17.14985 ZT4-7 14.4792 14.4792 14.4792 ZT8-11 15.6211 15.6211 15.6211 ZT12-15 15.05175 15.05175 15.05175 ZT16-19 21.8981 21.8981 21.8981 ZT20-23 18.545900000000003 18.545900000000003 18.545900000000003