condition mean min max ZT0-3 7.572775 7.572775 7.572775 ZT4-7 4.37477 4.37477 4.37477 ZT8-11 9.719370000000001 9.719370000000001 9.719370000000001 ZT12-15 11.8529 11.8529 11.8529 ZT16-19 13.6357 13.6357 13.6357 ZT20-23 8.512065 8.512065 8.512065