condition mean min max ZT0-3 18.9233061575 16.73240073 21.114211585 ZT4-7 17.251532855 15.18692579 19.31613992 ZT8-11 21.7749445675 19.89260487 23.657284265 ZT12-15 16.4861920725 13.852663435 19.11972071 ZT16-19 20.45981277 16.70905844 24.2105671 ZT20-23 41.535641277500005 33.157602940000004 49.913679615