condition mean min max ZT0-3 8.05703 8.05703 8.05703 ZT4-7 8.897836 8.897836 8.897836 ZT8-11 9.597798000000001 9.597798000000001 9.597798000000001 ZT12-15 8.3251955 8.3251955 8.3251955 ZT16-19 8.672291 8.672291 8.672291 ZT20-23 9.117978 9.117978 9.117978