condition mean min max ZT0-3 9.883596 9.883596 9.883596 ZT4-7 10.309814 10.309814 10.309814 ZT8-11 11.296254999999999 11.296254999999999 11.296254999999999 ZT12-15 8.3547115 8.3547115 8.3547115 ZT16-19 9.927189 9.927189 9.927189 ZT20-23 9.9416375 9.9416375 9.9416375