condition mean min max ZT0-3 12.875898 12.875898 12.875898 ZT4-7 11.718111 11.718111 11.718111 ZT8-11 11.1595685 11.1595685 11.1595685 ZT12-15 10.9047605 10.9047605 10.9047605 ZT16-19 11.860638 11.860638 11.860638 ZT20-23 14.343245 14.343245 14.343245