condition mean min max ZT0-3 9.968836179083333 9.3841090725 10.553563285666666 ZT4-7 9.225020020166667 6.729057804333334 11.720982236 ZT8-11 8.311160320499999 6.729917409 9.892403232 ZT12-15 8.197523390833332 7.904820780333333 8.490226001333333 ZT16-19 6.377292489 6.192923405 6.561661572999999 ZT20-23 6.006505703 5.9149826800000005 6.098028726