condition mean min max ZT0-3 21.0686 20.309849999999997 21.827350000000003 ZT4-7 8.14453 8.14453 8.14453 ZT8-11 13.44275 13.44275 13.44275 ZT12-15 0 0 0 ZT16-19 17.36725 17.36725 17.36725 ZT20-23 15.92075 15.92075 15.92075