condition mean min max ZT0-3 9.918354 9.918354 9.918354 ZT4-7 8.814832 8.814832 8.814832 ZT8-11 11.546275999999999 11.546275999999999 11.546275999999999 ZT12-15 11.8242735 11.8242735 11.8242735 ZT16-19 13.4602435 13.4602435 13.4602435 ZT20-23 12.626448499999999 12.626448499999999 12.626448499999999