High prevalence of stunting in women of reproductive age when simulation ran at length

[joehcollins]

As discussed with @inesll. Incidence parameter for stunting in the model is high (0.8) leading to a high proportion of stunted women of reproductive age (19% of women aged 15-49 by 2030 on 2000 population). This is currently leading to a growing rate of obstructed labour over time.

Need to check the assumed adult prevalence of being previously stunted in Malawi and calibrate the model accordingly.

[joehcollins]

@EvaJanouskova - just linking you in to this old issue that it would be good to check once the new version of stunting is in.