condition mean min max ZT0-3 6.3357850000000004 5.9519 6.754675000000001 ZT4-7 8.198285 8.198285 8.198285 ZT8-11 6.49255 6.49255 6.49255 ZT12-15 5.9008325 4.975115000000001 6.82655 ZT16-19 6.757705 6.757705 6.757705 ZT20-23 4.278215 4.278215 4.278215