condition mean min max ZT0-3 6.355223333333333 3.482805 8.05838 ZT4-7 3.70913 3.70913 3.70913 ZT8-11 4.383315 4.383315 4.383315 ZT12-15 3.793315 3.320595 4.2660350000000005 ZT16-19 4.513434999999999 4.513434999999999 4.513434999999999 ZT20-23 7.332345 7.332345 7.332345