condition mean min max ZT0-3 33.769125 33.158049999999996 34.3802 ZT4-7 19.272550000000003 19.272550000000003 19.272550000000003 ZT8-11 20.138599999999997 20.138599999999997 20.138599999999997 ZT12-15 0 0 0 ZT16-19 27.309150000000002 27.309150000000002 27.309150000000002 ZT20-23 29.16655 29.16655 29.16655