condition mean min max ZT0-3 5.937175 5.809365 6.064985 ZT4-7 5.52154 5.52154 5.52154 ZT8-11 4.564425 4.564425 4.564425 ZT12-15 0 0 0 ZT16-19 5.005330000000001 5.005330000000001 5.005330000000001 ZT20-23 5.758375 5.758375 5.758375