condition mean min max ZT0-3 4.294625 4.294625 4.294625 ZT4-7 3.3808350000000003 3.3808350000000003 3.3808350000000003 ZT8-11 3.215535 3.215535 3.215535 ZT12-15 3.5184100000000003 3.5184100000000003 3.5184100000000003 ZT16-19 4.028205 4.028205 4.028205 ZT20-23 5.167135 5.167135 5.167135