condition mean min max ZT0-3 3.6247499999999997 3.6247499999999997 3.6247499999999997 ZT4-7 3.2464049999999998 3.2464049999999998 3.2464049999999998 ZT8-11 2.3654650000000004 2.3654650000000004 2.3654650000000004 ZT12-15 2.002205 2.002205 2.002205 ZT16-19 2.88234 2.88234 2.88234 ZT20-23 2.92572 2.92572 2.92572