the cluster sample within the Galactic range covered by ATLASGAL, with many pieces of information, including: characteristics of the submm and mid-infrared emission, correlation with known objects, distances (kinematic and/or stellar), ages, and membership in big molecular complexes. A more detailed description of all the assumptions and procedures made when organizing this information in the catalog is given in Appendix \[sec:huge-table-details\]. In Section \[sec:analysis\], we report the results of a statistical analysis performed on this catalog, in which we delineate a morphological evolutionary sequence with decreasing correlation with ATLASGAL emission, classify the sample in ECs and OCs, and separately study their distance distribution, completeness, and age distribution. Finally, Section \[sec:conclusions\] summarizes the main conclusions of this paper.

Observations: Galactic surveys {#sec:galactic-surveys}
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The APEX Telescope Large Area Survey of the Galaxy [ATLASGAL, @Schuller2009] is the first unbiased submm continuum survey of the whole inner Galactic disk, covering a total of 360 square degrees of the sky with Galactic coordinates in the range $|\ell| \le 60\degr$ and $|b| \le 1.5\degr$. The observations were carried out at 870  using the Large APEX Bolometer Camera [LABOCA; @Siringo2009] of the APEX telescope [@Guensten2006], located on Llano de Chajnantor, Chile, at 5100 m of altitude. 