condition mean min max ZT0-3 18.222166666666666 14.2002 20.515900000000002 ZT4-7 11.67275 11.67275 11.67275 ZT8-11 16.7773 16.7773 16.7773 ZT12-15 29.348625 21.050150000000002 37.647099999999995 ZT16-19 29.6414 29.6414 29.6414 ZT20-23 27.735350000000004 27.735350000000004 27.735350000000004