condition mean min max ZT0-3 11.187496 11.187496 11.187496 ZT4-7 15.6180665 15.6180665 15.6180665 ZT8-11 12.4681935 12.4681935 12.4681935 ZT12-15 11.1732265 11.1732265 11.1732265 ZT16-19 10.9945735 10.9945735 10.9945735 ZT20-23 12.241555000000002 12.241555000000002 12.241555000000002