condition mean min max ZT0-3 6.352365 6.352365 6.352365 ZT4-7 10.02723 10.02723 10.02723 ZT8-11 4.50624 4.50624 4.50624 ZT12-15 2.995115 2.995115 2.995115 ZT16-19 3.391015 3.391015 3.391015 ZT20-23 4.933465 4.933465 4.933465