condition mean min max ZT0-3 15.999511955000001 15.43816937 16.56085454 ZT4-7 4.4811578025 4.291136699 4.671178906 ZT8-11 4.842134608249999 3.8472973025000003 5.836971913999999 ZT12-15 4.713166911 4.420462087 5.0058717349999995 ZT16-19 5.251752424249999 5.11219751 5.391307338499999 ZT20-23 7.01689049925 6.909136425 7.1246445734999995