Subfloor ventilation - to vent or not to vent?

It was said that sub-floor ventilation did not work. A basic exercise was undertaken to evaluate the effect of opening and closing airbricks. Whilst the data set was very LIMITED opening and closing vents did have an effect on the levels of subfloor atmospheric moisture

[@proggydan8257]

Earlier this year I insulated under suspended timber floor. There was plenty room under crawl space / sub floor. This week I went under again to inspect everything and noticed there is some mould developing and in one or two spots a little condensation. Temperatures have been high in my area of Scotland over the summer. I am wondering what I should do. Currently the space is ventilated by (probably not enough) air bricks.