condition mean min max ZT0-3 490.779454 490.779454 490.779454 ZT4-7 517.0948195 517.0948195 517.0948195 ZT8-11 319.7824905 319.7824905 319.7824905 ZT12-15 375.17584999999997 375.17584999999997 375.17584999999997 ZT16-19 310.0816455 310.0816455 310.0816455 ZT20-23 202.24314249999998 202.24314249999998 202.24314249999998