condition mean min max ZT0-3 18.209553875 14.243146450000001 22.1759613 ZT4-7 9.83881367975 9.0770635645 10.600563795 ZT8-11 13.3010096795 10.516623179 16.08539618 ZT12-15 17.0289345 15.382869199999998 18.6749998 ZT16-19 14.9609882225 13.68116482 16.240811625 ZT20-23 22.623499097499998 20.686742064999997 24.56025613