condition mean min max ZT0-3 4.821013333333333 4.06192 5.535575 ZT4-7 5.51774 5.51774 5.51774 ZT8-11 7.24777 7.24777 7.24777 ZT12-15 11.4857875 9.119575000000001 13.852 ZT16-19 7.934150000000001 7.934150000000001 7.934150000000001 ZT20-23 4.78445 4.78445 4.78445