condition mean min max ZT0-3 3.6998853333333335 2.3429349999999998 5.200495 ZT4-7 3.64081 3.64081 3.64081 ZT8-11 4.118115 4.118115 4.118115 ZT12-15 4.939465 4.617415 5.261515 ZT16-19 4.965389999999999 4.965389999999999 4.965389999999999 ZT20-23 3.5276949999999996 3.5276949999999996 3.5276949999999996