did not try to compute it in this paper (see Sect.\[discussion\]).\
The residuals of these fits are presented in Appendix\[sect:residuals\]. Tables\[tab:fluxes\] and \[tab:physpar\] summarize the average photometric measurements and the recovered physical parameters, respectively.\

Results
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Evolution of the mean SED of star-forming galaxies
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Figure\[fig:sedobs\] summarizes the results of our stacking analysis. For the main-sequence sample, the flux density varies rapidly with redshift in the PACS 100$\mu$m band, while it is almost constant in the SPIRE 500$\mu$m band. The peak of the flux density distribution in the rest frame moves from $\sim$120$\mu$m to 70$\mu$m between z=0 and z=4. This shift with redshift was already observed at z$\lesssim$2 for mass-selected stacked samples [@Magdis2012b] or a *Herschel*-detected sample [@Lee2013; @Symeonidis2013]. We found no evidence of an evolution of the position of this peak ($\sim$70$\mu$m) for the sample of strong starbursts.\
Figure\[fig:sedms\] and \[fig:sedsb\] show the mean intrinsic luminosity (in $\nu$L$_\nu$ units, the peak of the SEDs is thus shifted toward shorter wavelengths compared with L$_\nu$ units) of our samples of massive star-forming galaxies (since this sample is dominated by main-sequence galaxies, hereafter we call it main-sequence sample) and the fit by the @Draine2007 model. We also observe a strong evolution of 