condition mean min max ZT0-3 13.17557 13.17557 13.17557 ZT4-7 12.100985999999999 12.100985999999999 12.100985999999999 ZT8-11 11.9051535 11.9051535 11.9051535 ZT12-15 11.130295 11.130295 11.130295 ZT16-19 11.187495 11.187495 11.187495 ZT20-23 12.758928000000001 12.758928000000001 12.758928000000001