condition mean min max ZT0-3 6.447055000000001 6.447055000000001 6.447055000000001 ZT4-7 3.9537649999999998 3.9537649999999998 3.9537649999999998 ZT8-11 7.59159 7.59159 7.59159 ZT12-15 8.883395 8.883395 8.883395 ZT16-19 9.326505000000001 9.326505000000001 9.326505000000001 ZT20-23 9.077105 9.077105 9.077105