condition mean min max ZT0-3 15.800435 10.507655 19.60745 ZT4-7 6.896835 6.896835 6.896835 ZT8-11 6.861435 6.861435 6.861435 ZT12-15 20.75185 16.9857 24.518 ZT16-19 22.21515 22.21515 22.21515 ZT20-23 25.79655 25.79655 25.79655