gas - What is a typical value for core-to-star efficiency?

I was reading Unfolding the Laws of Star Formation: The Density Distribution of Molecular Clouds by Kainulainen et al., which discusses star formation rates and efficiencies.

One variable used is $varepsilon_{text{core}}$, the core-to-star efficiency, describing how much gas above the critical value of $s$, the logarithmic mean-normalized density, forms a star.

I'm using this parameter in some calculations, but I'd like to use an average value, as opposed to a value for a given molecular cloud.

What is a typical value for $varepsilon_{text{core}}$?

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