condition mean min max ZT0-3 14.450325 13.80025 15.1004 ZT4-7 9.109210000000001 9.109210000000001 9.109210000000001 ZT8-11 11.0195 11.0195 11.0195 ZT12-15 0 0 0 ZT16-19 12.1106 12.1106 12.1106 ZT20-23 12.142 12.142 12.142