While there are complicating factors, in general, probabilities add linearly. So for the average woman in the US, who lives for 77 years, she therefore has a 1% chance of being sexually harassed during any 1 year of her life. Obviously, this follows some distribution, but still, the odds of it happening in any one year of her life probably peaks around 5-10%.
I couldn't find good data on how many seasons the average Antarctic worker puts in, but let's say its around 10. That means the average woman working in Antarctica has a 5.9% chance of getting sexually harassed per year. Except, the average contract length in Antarctica is 4-6 months. So while a woman in the US has a 0.5% chance of being sexually harassed in a given 6 month time frame, a woman in Antarctica has an average 11.8% chance of being sexually harassed for the same time frame.
Do you understand the difference?