What were the wind speeds in the dust bowl in the 1930s

no , per capita income is not a true measure of the development because: -it only tells us about average income not how income is distributed among the people.it only give us an idea of the economic aspect.it is only at the qualitative basis.moreover, income is not only the way of development other factors are also as much as important as income.

could you go a bit more in depth with you question? it's quite hard to understand. as soon as you do that i will be glad to : )