condition mean min max ZT0-3 20.825975 19.70885 21.9431 ZT4-7 14.18225 14.18225 14.18225 ZT8-11 12.706800000000001 12.706800000000001 12.706800000000001 ZT12-15 0 0 0 ZT16-19 13.279 13.279 13.279 ZT20-23 17.2803 17.2803 17.2803