condition mean min max ZT0-3 4.354636666666667 3.679375 5.600265 ZT4-7 3.54683 3.54683 3.54683 ZT8-11 3.928985 3.928985 3.928985 ZT12-15 5.53139 4.147675 6.9151050000000005 ZT16-19 3.977965 3.977965 3.977965 ZT20-23 7.298805 7.298805 7.298805