Statistic Investigation

For the past few weeks, we have been doing statistical investigations.

What Did I learn?
I learnt that in 2011 the population went down a lot. The most likely reason is because of the earthquakes.

What would you do differently If you did it again?
If I did this again I would choose a different topic to study and maybe choose a topic to study and a new partner

Something I am wondering or a question I have after completing this work
I am interested in how they do the census do they go to each door asking "How much people are in this house?" or do they do to the hospital and ask "How many birth certificates do you have?" That is what I'm interested in