condition mean min max ZT0-3 17.500625 17.49705 17.504199999999997 ZT4-7 11.285250000000001 11.285250000000001 11.285250000000001 ZT8-11 16.8412 16.8412 16.8412 ZT12-15 0 0 0 ZT16-19 16.0024 16.0024 16.0024 ZT20-23 17.42785 17.42785 17.42785