condition mean min max ZT0-3 9.68322 9.68322 9.68322 ZT4-7 6.480565 6.480565 6.480565 ZT8-11 6.36201 6.36201 6.36201 ZT12-15 6.77473 6.77473 6.77473 ZT16-19 10.50915 10.50915 10.50915 ZT20-23 11.1387 11.1387 11.1387