condition mean min max ZT0-3 7.465145 7.465145 7.465145 ZT4-7 4.547225 4.547225 4.547225 ZT8-11 4.322185 4.322185 4.322185 ZT12-15 6.278245 6.278245 6.278245 ZT16-19 11.6909 11.6909 11.6909 ZT20-23 6.235335 6.235335 6.235335