condition mean min max ZT0-3 7.23239 7.23239 7.23239 ZT4-7 7.5799025 7.5799025 7.5799025 ZT8-11 8.832748 8.832748 8.832748 ZT12-15 8.0485005 8.0485005 8.0485005 ZT16-19 8.3384325 8.3384325 8.3384325 ZT20-23 8.769597000000001 8.769597000000001 8.769597000000001