condition mean min max ZT0-3 8.941741 8.941741 8.941741 ZT4-7 9.712356 9.712356 9.712356 ZT8-11 9.4511175 9.4511175 9.4511175 ZT12-15 10.319066 10.319066 10.319066 ZT16-19 9.0349905 9.0349905 9.0349905 ZT20-23 11.125325499999999 11.125325499999999 11.125325499999999