condition mean min max ZT0-3 0.43336383333333334 0.252293 0.679705 ZT4-7 0.5940245 0.5940245 0.5940245 ZT8-11 0.9740385 0.9740385 0.9740385 ZT12-15 1.7579124999999998 1.46282 2.0530049999999997 ZT16-19 0.40827899999999995 0.40827899999999995 0.40827899999999995 ZT20-23 0.7144825 0.7144825 0.7144825