condition mean min max ZT0-3 4.835913333333333 4.736945 5.01967 ZT4-7 5.62896 5.62896 5.62896 ZT8-11 5.522325 5.522325 5.522325 ZT12-15 8.3812875 7.262915 9.49966 ZT16-19 8.479085 8.479085 8.479085 ZT20-23 9.57535 9.57535 9.57535