Questions are to be framed according to the variance in the given data.
Step-by-step explanation:
Q1: Why there is no data available for Illinois?
The answer is rather simple in that the state of Illinois did not exist in 1810
Q2: What is the reason of rapid increase in the population in all the states.
States like Ohio saw a massive population boom in the first few decades of the century, primarily due to expansion.
Q3: How come all three states grew in population at a similar rate throughout?
Very similar methods of expansion and population growth must be responsible for these numbers. The socio economic strata being similar also plays a role here.