condition mean min max ZT0-3 11.77385 11.570450000000001 11.97725 ZT4-7 11.9359 11.9359 11.9359 ZT8-11 18.5136 18.5136 18.5136 ZT12-15 0 0 0 ZT16-19 18.3417 18.3417 18.3417 ZT20-23 16.62115 16.62115 16.62115