condition mean min max ZT0-3 7.5074 7.5074 7.5074 ZT4-7 8.366800999999999 8.366800999999999 8.366800999999999 ZT8-11 8.0110235 8.0110235 8.0110235 ZT12-15 7.929721499999999 7.929721499999999 7.929721499999999 ZT16-19 7.851725 7.851725 7.851725 ZT20-23 8.63631 8.63631 8.63631