condition mean min max ZT0-3 7.07433 5.390224999999999 8.623695 ZT4-7 4.7056249999999995 4.7056249999999995 4.7056249999999995 ZT8-11 4.423220000000001 4.423220000000001 4.423220000000001 ZT12-15 6.163645 5.724385 6.602905 ZT16-19 6.52438 6.52438 6.52438 ZT20-23 8.609465 8.609465 8.609465