condition mean min max ZT0-3 253.617314 253.617314 253.617314 ZT4-7 476.77933 476.77933 476.77933 ZT8-11 416.124458 416.124458 416.124458 ZT12-15 540.3113435 540.3113435 540.3113435 ZT16-19 248.50873049999998 248.50873049999998 248.50873049999998 ZT20-23 78.2353665 78.2353665 78.2353665