condition mean min max ZT0-3 9.98263 4.093005 15.50705 ZT4-7 7.175755 7.175755 7.175755 ZT8-11 6.750195 6.750195 6.750195 ZT12-15 4.5679425 4.124345 5.01154 ZT16-19 6.99231 6.99231 6.99231 ZT20-23 8.7043 8.7043 8.7043