condition mean min max ZT0-3 21.838776 21.838776 21.838776 ZT4-7 20.1899455 20.1899455 20.1899455 ZT8-11 18.802571 18.802571 18.802571 ZT12-15 19.469556 19.469556 19.469556 ZT16-19 19.515324 19.515324 19.515324 ZT20-23 28.183847 28.183847 28.183847