condition mean min max ZT0-3 1.8160675 1.530935 2.1012 ZT4-7 2.518665 2.518665 2.518665 ZT8-11 4.10444 4.10444 4.10444 ZT12-15 0 0 0 ZT16-19 2.7193300000000002 2.7193300000000002 2.7193300000000002 ZT20-23 3.763655 3.763655 3.763655