condition mean min max ZT0-3 4.772724999999999 4.772724999999999 4.772724999999999 ZT4-7 3.18113 3.18113 3.18113 ZT8-11 6.9856300000000005 6.9856300000000005 6.9856300000000005 ZT12-15 6.366265 6.366265 6.366265 ZT16-19 6.67171 6.67171 6.67171 ZT20-23 4.516975 4.516975 4.516975