Over the last 6 years of Ironman 70.3 women have consistently made up 25% of all entrants. Here I look at how gender ratios have varied over time and across Ironman regions.
Gender Totals

As the number of Ironman 70.3 competitors has grown the proportion of women competing has remained at a consistent 25%. This is slightly higher than the 20% figure seen for full-distance Ironman racing.
Regional Totals

Variation in gender ratios across Ironman 70.3 regions also share many similarities with Ironman. Again, the proportion of women racing 70.3 is higher in each region. In particular it's regions like Europe, Asia and South America, which saw lower proportions of women at Ironman that have a larger increase in ratio at Ironman 70.3.
More Demographics
You can continue exploring 2019 Ironman 70.3 Demographics below with more detail on overall entrants, plus age group and nationality of competitors.