condition mean min max ZT0-3 150.825945 150.825945 150.825945 ZT4-7 256.535527 256.535527 256.535527 ZT8-11 229.585063 229.585063 229.585063 ZT12-15 198.66771999999997 198.66771999999997 198.66771999999997 ZT16-19 278.264104 278.264104 278.264104 ZT20-23 237.440923 237.440923 237.440923