condition mean min max ZT0-3 4.40108569975 3.2201674264999998 5.582003973 ZT4-7 3.26581677225 3.0969326125 3.434700932 ZT8-11 2.23856427675 1.9022065554999998 2.574921998 ZT12-15 1.44037480125 1.373116604 1.5076329984999999 ZT16-19 1.88853312725 1.4102492105 2.3668170440000003 ZT20-23 3.15174768625 3.0126284565 3.2908669159999997