condition mean min max ZT0-3 14.972171 14.972171 14.972171 ZT4-7 12.265723999999999 12.265723999999999 12.265723999999999 ZT8-11 13.001032 13.001032 13.001032 ZT12-15 13.487152 13.487152 13.487152 ZT16-19 12.3014445 12.3014445 12.3014445 ZT20-23 13.4004665 13.4004665 13.4004665