condition mean min max ZT0-3 8.879892 8.879892 8.879892 ZT4-7 11.4297965 11.4297965 11.4297965 ZT8-11 9.7180605 9.7180605 9.7180605 ZT12-15 9.918354 9.918354 9.918354 ZT16-19 10.199894 10.199894 10.199894 ZT20-23 9.624363500000001 9.624363500000001 9.624363500000001