condition mean min max ZT0-3 2.981935 2.977245 2.986625 ZT4-7 2.88753 2.88753 2.88753 ZT8-11 4.71804 4.71804 4.71804 ZT12-15 0 0 0 ZT16-19 6.52 6.52 6.52 ZT20-23 4.9074349999999995 4.9074349999999995 4.9074349999999995