condition mean min max ZT0-3 7.835337 7.835337 7.835337 ZT4-7 8.847615000000001 8.847615000000001 8.847615000000001 ZT8-11 8.705426 8.705426 8.705426 ZT12-15 9.611369 9.611369 9.611369 ZT16-19 8.294073000000001 8.294073000000001 8.294073000000001 ZT20-23 8.1422925 8.1422925 8.1422925