condition mean min max ZT0-3 3.36807 2.1665200000000002 4.0933399999999995 ZT4-7 1.6414 1.6414 1.6414 ZT8-11 2.74091 2.74091 2.74091 ZT12-15 4.125795 3.882145 4.369445 ZT16-19 5.489535 5.489535 5.489535 ZT20-23 5.232555 5.232555 5.232555