user
Instruction
Answer the question based on the provided table.


Table
Table Title: geometric means of urinary bpa concentrations, by selected characteristics, household population aged 6 to 17, canada, 2007/2009 and 2009/2011
Table Content:
<table border="1" cellspacing="0">
<tr> <td rowspan="2"> characteristics </td> <td rowspan="2"> geometric mean </td> <td colspan="2"> 95% confidence interval </td> </tr>
<tr> <td> from </td> <td> to </td> </tr>
<tr> <td> total </td> <td> 1.3 </td> <td> 1.1 </td> <td> 1.4 </td> </tr>
<tr> <td> age group </td> <td colspan="3">  </td> </tr>
<tr> <td> 6 to 8 </td> <td> 1.8 </td> <td> 1.6 </td> <td> 2.1 </td> </tr>
<tr> <td> 9 to 11 </td> <td> 1.4 </td> <td> 1.2 </td> <td> 1.7 </td> </tr>
<tr> <td> 12 to 14 </td> <td> 1.2 </td> <td> 1.0 </td> <td> 1.4 </td> </tr>
<tr> <td> 15 to 17 </td> <td> 0.9 </td> <td> 0.8 </td> <td> 1.1 </td> </tr>
<tr> <td> sex </td> <td colspan="3">  </td> </tr>
<tr> <td> male </td> <td> 1.2 </td> <td> 1.1 </td> <td> 1.4 </td> </tr>
<tr> <td> female </td> <td> 1.3 </td> <td> 1.2 </td> <td> 1.5 </td> </tr>
<tr> <td> time of urine collection </td> <td colspan="3">  </td> </tr>
<tr> <td> morning </td> <td> 1.1 </td> <td> 1.0 </td> <td> 1.3 </td> </tr>
<tr> <td> afternoon </td> <td> 1.5 </td> <td> 1.3 </td> <td> 1.7 </td> </tr>
<tr> <td> evening </td> <td> 1.4 </td> <td> 1.0 </td> <td> 1.7 </td> </tr>
<tr> <td> ethnicity </td> <td colspan="3">  </td> </tr>
<tr> <td> white </td> <td> 1.3 </td> <td> 1.2 </td> <td> 1.5 </td> </tr>
<tr> <td> non-white </td> <td> 1.3 </td> <td> 1.0 </td> <td> 1.6 </td> </tr>
<tr> <td> exposure to second-hand smoke </td> <td colspan="3">  </td> </tr>
<tr> <td> once a week or less </td> <td> 1.2 </td> <td> 1.1 </td> <td> 1.4 </td> </tr>
<tr> <td> every day or almost every day </td> <td> 1.6 </td> <td> 1.4 </td> <td> 2.0 </td> </tr>
<tr> <td> household income </td> <td colspan="3">  </td> </tr>
<tr> <td> low/lower-middle </td> <td> 1.7 </td> <td> 1.4 </td> <td> 2.0 </td> </tr>
<tr> <td> upper-middle </td> <td> 1.2 </td> <td> 1.0 </td> <td> 1.4 </td> </tr>
<tr> <td> highest </td> <td> 1.2 </td> <td> 1.1 </td> <td> 1.4 </td> </tr>
<tr> <td> household education </td> <td colspan="3">  </td> </tr>
<tr> <td> secondary school graduation or less </td> <td> 1.3 </td> <td> 1.0 </td> <td> 1.6 </td> </tr>
<tr> <td> at least some postsecondary </td> <td> 1.3 </td> <td> 1.1 </td> <td> 1.5 </td> </tr>
<tr> <td> body mass index </td> <td colspan="3">  </td> </tr>
<tr> <td> neither overweight nor obese </td> <td> 1.3 </td> <td> 1.2 </td> <td> 1.5 </td> </tr>
<tr> <td> overweight </td> <td> 1.3 </td> <td> 1.0 </td> <td> 1.7 </td> </tr>
<tr> <td> obese </td> <td> 1.2 </td> <td> 1.0 </td> <td> 1.4 </td> </tr>
</table>


Question
which age group had the highest bpa concentrations?


Answer Format
The final answer should be concise and use the following format:
```json
{
    "answer": [
        "answer1",
        "answer2",
        ...
    ]
}
```
rule
["6 to 8"]