reality about twitter is that majority of the people on it rarely tweet. 
we may have 10, 000 kenyans on twitter but only roughly 50 of those
tweet on a regular basis.  

The rest just check their timelines for updates or have dead accounts 
either way only twitter can tell.

Back to my point the kenyatweets does not explain the algorithm they use
to get the trending topics as they appear either as not updated or manually 
inserted.

The number of kenyans on twitter is really irrelevant.

1. Some users tweet from more than one account (i have 5 accounts)
2. Some users dont tweet at all 
3. Most of the tweets are spam or FB crap! whih has no value at all i.e
    why would you tell your followers you just woke up if you are not a celebrity

The relevance of information in tweets is more important and thus should be the 
focus of any analysis.