condition mean min max ZT0-3 9.293585 9.293585 9.293585 ZT4-7 8.913630000000001 8.913630000000001 8.913630000000001 ZT8-11 8.33885 8.33885 8.33885 ZT12-15 8.592385 8.592385 8.592385 ZT16-19 9.038845 9.038845 9.038845 ZT20-23 8.828990000000001 8.828990000000001 8.828990000000001