condition mean min max ZT0-3 23.76285 23.76285 23.76285 ZT4-7 15.26115 15.26115 15.26115 ZT8-11 12.89275 12.89275 12.89275 ZT12-15 21.974449999999997 21.974449999999997 21.974449999999997 ZT16-19 24.7667 24.7667 24.7667 ZT20-23 31.241 31.241 31.241