condition mean min max ZT0-3 11.45844 9.71323 13.20365 ZT4-7 5.85936 5.85936 5.85936 ZT8-11 12.19355 12.19355 12.19355 ZT12-15 0 0 0 ZT16-19 13.80235 13.80235 13.80235 ZT20-23 6.565385 6.565385 6.565385