condition mean min max ZT0-3 9.16641 9.16641 9.16641 ZT4-7 8.5409215 8.5409215 8.5409215 ZT8-11 7.9960865 7.9960865 7.9960865 ZT12-15 9.2849185 9.2849185 9.2849185 ZT16-19 8.9335625 8.9335625 8.9335625 ZT20-23 8.479056499999999 8.479056499999999 8.479056499999999