Pod iterates on header, not row

I have a two lines template in calc :
First line is header
| Institution | Nombre | Durée Moyenne |
Second line is
| ="institution[‘Institution’]" | ="institution[‘Nombre’]" | ="institution[‘Durée moyenne’]" |
Then I added a comment on the whole second row :
do row for institution in agrements

Then I run my script :

from script_pandas import report_data
from appy.pod.renderer import Renderer

for r in report_data:
    renderer = Renderer(
        'bilan.ods',
        {
            'agrements': report_data[r]['agrements'],
            'entrees': report_data[r]['entrees']
        },
        'output/bilan_%s.ods' %(r)
    )
    renderer.run()

And I get this :
| Institution | Nombre | Durée Moyenne |
| Institution | Nombre | Durée Moyenne |
| Institution | Nombre | Durée Moyenne |
| Institution | Nombre | Durée Moyenne |
| Institution | Nombre | Durée Moyenne |
| | | |

It's almost working because agrements is a 5elements list. What did I do wrong?
It's obvious that pod iterated on the header instead of the row, but I don't understand why...
Thanks for this great tool.