condition mean min max ZT0-3 1.3071573333333335 0.315612 1.90802 ZT4-7 0.248029 0.248029 0.248029 ZT8-11 0.45987900000000004 0.45987900000000004 0.45987900000000004 ZT12-15 0.85091125 0.5313075 1.170515 ZT16-19 1.1126865000000001 1.1126865000000001 1.1126865000000001 ZT20-23 1.70283 1.70283 1.70283