condition mean min max ZT0-3 397.298016 397.298016 397.298016 ZT4-7 336.2496175 336.2496175 336.2496175 ZT8-11 337.51374699999997 337.51374699999997 337.51374699999997 ZT12-15 316.5902565 316.5902565 316.5902565 ZT16-19 258.62433450000003 258.62433450000003 258.62433450000003 ZT20-23 227.356515 227.356515 227.356515