condition mean min max ZT0-3 333.7011111 333.7011111 333.7011111 ZT4-7 302.1188889 302.1188889 302.1188889 ZT8-11 276.0988889 276.0988889 276.0988889 ZT12-15 216.7666667 216.7666667 216.7666667 ZT16-19 256.8122222 256.8122222 256.8122222 ZT20-23 280.4011111 280.4011111 280.4011111