condition mean min max ZT0-3 1.214522 1.214522 1.214522 ZT4-7 0.727662 0.727662 0.727662 ZT8-11 0.6325965 0.6325965 0.6325965 ZT12-15 0.8004465000000001 0.8004465000000001 0.8004465000000001 ZT16-19 0.8449409999999999 0.8449409999999999 0.8449409999999999 ZT20-23 1.15493 1.15493 1.15493