condition mean min max ZT0-3 384.131473 384.131473 384.131473 ZT4-7 364.878696 364.878696 364.878696 ZT8-11 423.42373299999997 423.42373299999997 423.42373299999997 ZT12-15 574.8133775 574.8133775 574.8133775 ZT16-19 633.0605635 633.0605635 633.0605635 ZT20-23 1302.519867 1302.519867 1302.519867