condition mean min max ZT0-3 6.768285 4.25347 8.48123 ZT4-7 4.01811 4.01811 4.01811 ZT8-11 5.81864 5.81864 5.81864 ZT12-15 8.400392499999999 7.50192 9.298865 ZT16-19 8.995975 8.995975 8.995975 ZT20-23 11.054400000000001 11.054400000000001 11.054400000000001