condition mean min max ZT0-3 4.087304705499999 4.030741572 4.143867838999999 ZT4-7 4.624185239 3.9400764400000003 5.308294038 ZT8-11 2.9314763330000004 2.8680660295000004 2.9948866365000004 ZT12-15 8.226098401 5.1868894354999995 11.2653073665 ZT16-19 18.64803373 18.49236561 18.80370185 ZT20-23 41.467181672500004 33.997004360000005 48.937358985