[α/Fe] versus age distribution for the MSTO+SGB samples of each survey. A cleaning per signal to noise and suggested flags was performed. The purple squares show the median trend per bin in [α/Fe], while the error bars show its one σ deviation. We only display the surveys that have mean statistical uncertainty in age < 20% according to Table 2 (no RAVE or Gaia RVS). We also performed a cleaning of flags in the [α/Fe] determination from each survey.