condition mean min max ZT0-3 14.836825000000001 6.218675 19.1809 ZT4-7 8.57643 8.57643 8.57643 ZT8-11 6.752759999999999 6.752759999999999 6.752759999999999 ZT12-15 8.585895 7.50146 9.67033 ZT16-19 8.998785 8.998785 8.998785 ZT20-23 14.358460000000001 14.358460000000001 14.358460000000001