condition mean min max ZT0-3 9.2395 9.2395 9.2395 ZT4-7 2.9870799999999997 2.9870799999999997 2.9870799999999997 ZT8-11 5.53204 5.53204 5.53204 ZT12-15 21.3747 21.3747 21.3747 ZT16-19 27.52115 27.52115 27.52115 ZT20-23 18.708599999999997 18.708599999999997 18.708599999999997