condition mean min max ZT0-3 8.874598333333333 6.419829999999999 10.18804 ZT4-7 7.48331 7.48331 7.48331 ZT8-11 4.4796949999999995 4.4796949999999995 4.4796949999999995 ZT12-15 5.7701025 5.2637350000000005 6.27647 ZT16-19 6.571949999999999 6.571949999999999 6.571949999999999 ZT20-23 6.59374 6.59374 6.59374