condition mean min max ZT0-3 10.415586 10.415586 10.415586 ZT4-7 12.7835965 12.7835965 12.7835965 ZT8-11 12.172304 12.172304 12.172304 ZT12-15 11.5008595 11.5008595 11.5008595 ZT16-19 13.658425 13.658425 13.658425 ZT20-23 12.0098625 12.0098625 12.0098625