condition mean min max ZT0-3 10.96485 10.96485 10.96485 ZT4-7 8.40854 8.40854 8.40854 ZT8-11 9.92625 9.92625 9.92625 ZT12-15 12.5627 12.5627 12.5627 ZT16-19 13.5267 13.5267 13.5267 ZT20-23 11.8461 11.8461 11.8461