condition mean min max ZT0-3 17.3 17.3 17.3 ZT4-7 22.6 22.6 22.6 ZT8-11 31.9 31.9 31.9 ZT12-15 60.699999999999996 60.699999999999996 60.699999999999996 ZT16-19 120.05000000000001 120.05000000000001 120.05000000000001 ZT20-23 43.949999999999996 43.949999999999996 43.949999999999996