condition mean min max ZT0-3 11.805043 11.805043 11.805043 ZT4-7 13.6942785 13.6942785 13.6942785 ZT8-11 12.9314045 12.9314045 12.9314045 ZT12-15 11.303747999999999 11.303747999999999 11.303747999999999 ZT16-19 11.9565485 11.9565485 11.9565485 ZT20-23 12.26492 12.26492 12.26492