condition mean min max ZT0-3 20.691301666666668 9.470805 29.1806 ZT4-7 8.224585 8.224585 8.224585 ZT8-11 6.417415 6.417415 6.417415 ZT12-15 12.924150000000001 12.84225 13.00605 ZT16-19 17.79735 17.79735 17.79735 ZT20-23 31.370400000000004 31.370400000000004 31.370400000000004