condition mean min max ZT0-3 9.0971325 8.371495 9.82277 ZT4-7 6.55485 6.55485 6.55485 ZT8-11 19.37525 19.37525 19.37525 ZT12-15 0 0 0 ZT16-19 15.137699999999999 15.137699999999999 15.137699999999999 ZT20-23 11.8305 11.8305 11.8305