condition mean min max ZT0-3 6.949999999999999 6.949999999999999 6.949999999999999 ZT4-7 19.0 19.0 19.0 ZT8-11 7.6 7.6 7.6 ZT12-15 8.75 8.75 8.75 ZT16-19 8.4 8.4 8.4 ZT20-23 10.0 10.0 10.0