condition mean min max ZT0-3 7.317444999999999 7.317444999999999 7.317444999999999 ZT4-7 6.17834 6.17834 6.17834 ZT8-11 6.118245 6.118245 6.118245 ZT12-15 6.259715 6.259715 6.259715 ZT16-19 7.34317 7.34317 7.34317 ZT20-23 6.906874999999999 6.906874999999999 6.906874999999999