condition mean min max ZT0-3 14.608425 14.17835 15.0385 ZT4-7 19.91405 19.91405 19.91405 ZT8-11 20.975 20.975 20.975 ZT12-15 0 0 0 ZT16-19 27.69775 27.69775 27.69775 ZT20-23 21.5974 21.5974 21.5974