condition mean min max ZT0-3 7.33537 6.106695 8.564045 ZT4-7 7.166345 7.166345 7.166345 ZT8-11 8.41231 8.41231 8.41231 ZT12-15 0 0 0 ZT16-19 10.069514999999999 10.069514999999999 10.069514999999999 ZT20-23 9.61717 9.61717 9.61717