condition mean min max ZT0-3 18.2611 18.2611 18.2611 ZT4-7 3.733385 3.733385 3.733385 ZT8-11 8.823895 8.823895 8.823895 ZT12-15 13.4219 13.4219 13.4219 ZT16-19 25.66465 25.66465 25.66465 ZT20-23 31.157049999999998 31.157049999999998 31.157049999999998