Emigrants from very small countries sure to get US green cards?

The Green Card lottery gives away permanent work and living permits to people chosen at random. Different quantities of visas are allocated to being given away in different countries based on how many people from these countries immigrated in the last few years.

Now I’d like to know if very small countries, which can definitely not have sent many immigrAnts since their populations are small, have a very high chance of getting green cards for almost all of their citizens willing to get one because they have such a low number of emigrants and are therefore not really limited in their quota?

I mean, if my home country, where a little over 500.000 people live, has about 20 or 30 people asking for a green card every year, are they sure to get one because other countries have thousands of people immigrating to the US and tiny countries are negligeable or is there an overall percentage of Green Card applicants for every country that is approved, so that even if there were only 5 applicants in a country some of them would be bound to be denied a Green Card?