condition mean min max ZT0-3 9.200357 9.200357 9.200357 ZT4-7 9.949676 9.949676 9.949676 ZT8-11 9.3196355 9.3196355 9.3196355 ZT12-15 9.4086575 9.4086575 9.4086575 ZT16-19 8.7938415 8.7938415 8.7938415 ZT20-23 9.423368499999999 9.423368499999999 9.423368499999999