condition mean min max ZT0-3 6.416980000000001 6.416980000000001 6.416980000000001 ZT4-7 4.25847 4.25847 4.25847 ZT8-11 4.88203 4.88203 4.88203 ZT12-15 5.467455 5.467455 5.467455 ZT16-19 7.73879 7.73879 7.73879 ZT20-23 6.518805 6.518805 6.518805