condition mean min max ZT0-3 1.5804725 1.2338200000000001 1.927125 ZT4-7 3.6098049999999997 3.6098049999999997 3.6098049999999997 ZT8-11 18.572699999999998 18.572699999999998 18.572699999999998 ZT12-15 0 0 0 ZT16-19 9.208345000000001 9.208345000000001 9.208345000000001 ZT20-23 5.385135 5.385135 5.385135