condition mean min max ZT0-3 11.512 11.4814 11.5426 ZT4-7 6.953425 6.953425 6.953425 ZT8-11 6.64574 6.64574 6.64574 ZT12-15 0 0 0 ZT16-19 14.019949999999998 14.019949999999998 14.019949999999998 ZT20-23 13.2351 13.2351 13.2351