Line graphs are easier to see the change over time for a particular metric. Colors will need more contrast (with consideration to color-blind users) since they will be smaller. Each line should be labeled with the metric it's measuring. Consider showing one graph for raw population numbers and another showing the percentage of the population by the amount of their income they spend on housing. Maybe another graph overlaying average housing cost (rent and/or mortgage) with the percentage of income spent on housing.
Line graphs are easier to see the change over time for a particular metric. Colors will need more contrast (with consideration to color-blind users) since they will be smaller. Each line should be labeled with the metric it's measuring. Consider showing one graph for raw population numbers and another showing the percentage of the population by the amount of their income they spend on housing. Maybe another graph overlaying average housing cost (rent and/or mortgage) with the percentage of income spent on housing.