condition mean min max ZT0-3 13.699415 13.699415 13.699415 ZT4-7 14.1883555 14.1883555 14.1883555 ZT8-11 13.739907500000001 13.739907500000001 13.739907500000001 ZT12-15 16.022511 16.022511 16.022511 ZT16-19 19.300469 19.300469 19.300469 ZT20-23 18.9925875 18.9925875 18.9925875