condition mean min max ZT0-3 8.89586 8.89586 8.89586 ZT4-7 8.741607 8.741607 8.741607 ZT8-11 8.8042985 8.8042985 8.8042985 ZT12-15 10.122936 10.122936 10.122936 ZT16-19 9.199798000000001 9.199798000000001 9.199798000000001 ZT20-23 9.4319775 9.4319775 9.4319775