condition mean min max ZT0-3 2.7317475 2.184125 3.27937 ZT4-7 1.6438700000000002 1.6438700000000002 1.6438700000000002 ZT8-11 0.883124 0.883124 0.883124 ZT12-15 0 0 0 ZT16-19 1.7254049999999999 1.7254049999999999 1.7254049999999999 ZT20-23 3.69812 3.69812 3.69812