condition mean min max ZT0-3 8.148074999999999 8.148074999999999 8.148074999999999 ZT4-7 7.817745 7.817745 7.817745 ZT8-11 8.52787 8.52787 8.52787 ZT12-15 9.479605 9.479605 9.479605 ZT16-19 8.338405 8.338405 8.338405 ZT20-23 6.884845 6.884845 6.884845