Along with what tranthidung suggested, you could also add statistics on how much the word "bitcoin" is being searched on Google from people in Bangladesh, using Google Trends:
Personally, Google Trend should be used as an supplementary source or as a main source if you can not find any better data because of their low, biased quality.
- Search # usages
- Search can reflect interests (in mind) and from it to expand to create accounts or fill capital into accounts for bitcoin investment, it is a long story.
- Search can increase with bitcoin bull run or decrease with bitcoin bear run
- Search can be biased by hot news: billions of dollar in bitcoin was hacked on exchange A, ie. or law regulations.
With Google Trend, you don't know chronological activities of searchers:
- Why people made their searching
- What they search together with Bitcoin (bitcoin scam, bitcoin hack, bitcoin billion, etc.)
- What they did after that
