condition mean min max ZT0-3 10.769513 10.769513 10.769513 ZT4-7 10.994959999999999 10.994959999999999 10.994959999999999 ZT8-11 12.6410725 12.6410725 12.6410725 ZT12-15 10.2756615 10.2756615 10.2756615 ZT16-19 10.4644335 10.4644335 10.4644335 ZT20-23 11.2973465 11.2973465 11.2973465