condition mean min max ZT0-3 2.819445 2.819445 2.819445 ZT4-7 1.4222450000000002 1.4222450000000002 1.4222450000000002 ZT8-11 2.511885 2.511885 2.511885 ZT12-15 3.22059 3.22059 3.22059 ZT16-19 3.510825 3.510825 3.510825 ZT20-23 3.18032 3.18032 3.18032