condition mean min max ZT0-3 234.598362 234.598362 234.598362 ZT4-7 227.88357249999999 227.88357249999999 227.88357249999999 ZT8-11 184.275747 184.275747 184.275747 ZT12-15 218.0889955 218.0889955 218.0889955 ZT16-19 163.84365400000002 163.84365400000002 163.84365400000002 ZT20-23 153.326611 153.326611 153.326611