condition mean min max ZT0-3 2.608025 2.608025 2.608025 ZT4-7 0.9711350000000001 0.9711350000000001 0.9711350000000001 ZT8-11 1.623965 1.623965 1.623965 ZT12-15 3.999765 3.999765 3.999765 ZT16-19 6.178990000000001 6.178990000000001 6.178990000000001 ZT20-23 7.06738 7.06738 7.06738