condition mean min max ZT0-3 11.909987 11.909987 11.909987 ZT4-7 12.946493 12.946493 12.946493 ZT8-11 16.196453 16.196453 16.196453 ZT12-15 13.123865 13.123865 13.123865 ZT16-19 11.1452855 11.1452855 11.1452855 ZT20-23 11.4181405 11.4181405 11.4181405