condition mean min max ZT0-3 11.959999999 11.959999999 11.959999999 ZT4-7 6.575 6.575 6.575 ZT8-11 7.885 7.885 7.885 ZT12-15 6.108888888999999 6.108888888999999 6.108888888999999 ZT16-19 4.404444444666667 4.404444444666667 4.404444444666667 ZT20-23 4.945555555666667 4.945555555666667 4.945555555666667