condition mean min max ZT0-3 8.2592 8.2592 8.2592 ZT4-7 4.816015 4.816015 4.816015 ZT8-11 5.205735 5.205735 5.205735 ZT12-15 6.9262999999999995 6.9262999999999995 6.9262999999999995 ZT16-19 9.83338 9.83338 9.83338 ZT20-23 8.487665 8.487665 8.487665