condition mean min max ZT0-3 12.959673 12.959673 12.959673 ZT4-7 13.346938999999999 13.346938999999999 13.346938999999999 ZT8-11 14.963969500000001 14.963969500000001 14.963969500000001 ZT12-15 13.411158499999999 13.411158499999999 13.411158499999999 ZT16-19 11.848469000000001 11.848469000000001 11.848469000000001 ZT20-23 11.6435975 11.6435975 11.6435975