condition mean min max ZT0-3 3.97789 3.97789 3.97789 ZT4-7 2.27215 2.27215 2.27215 ZT8-11 3.7817550000000004 3.7817550000000004 3.7817550000000004 ZT12-15 4.059205 4.059205 4.059205 ZT16-19 7.087755 7.087755 7.087755 ZT20-23 4.452640000000001 4.452640000000001 4.452640000000001