condition mean min max ZT0-3 9.590472 9.590472 9.590472 ZT4-7 8.179463 8.179463 8.179463 ZT8-11 10.2350575 10.2350575 10.2350575 ZT12-15 9.7311845 9.7311845 9.7311845 ZT16-19 10.189409999999999 10.189409999999999 10.189409999999999 ZT20-23 10.417534 10.417534 10.417534