condition mean min max ZT0-3 3.242678333333333 2.174365 4.2843599999999995 ZT4-7 2.916585 2.916585 2.916585 ZT8-11 5.252784999999999 5.252784999999999 5.252784999999999 ZT12-15 10.199265 8.959330000000001 11.4392 ZT16-19 7.161235 7.161235 7.161235 ZT20-23 5.219475 5.219475 5.219475