condition mean min max ZT0-3 15.341971 15.341971 15.341971 ZT4-7 10.5971165 10.5971165 10.5971165 ZT8-11 8.2377935 8.2377935 8.2377935 ZT12-15 12.8967775 12.8967775 12.8967775 ZT16-19 10.288055 10.288055 10.288055 ZT20-23 13.676469 13.676469 13.676469