condition mean min max ZT0-3 12.616129 12.616129 12.616129 ZT4-7 13.6888905 13.6888905 13.6888905 ZT8-11 13.995661 13.995661 13.995661 ZT12-15 13.873886500000001 13.873886500000001 13.873886500000001 ZT16-19 14.067026 14.067026 14.067026 ZT20-23 13.7794315 13.7794315 13.7794315