Mobile phone ownership in Kenya, home of the world’s largest mobile money platform and one of Africa’s most mobile friendly economies, is a little lower than previously thought.

The Communications Authority of Kenya, which releases quarterly data on the sector, has revised its data collection method to include only phone lines that have used a revenue generating service in the last 90 days. According to its report for July through September last year, Kenya’s mobile subscriptions were 38.5 million, a 3% decline from the 39.7 million reported in the previous quarter.

That brings mobile penetration in Kenya’s 44 million large population down to 87%, from 90% the quarter before. (The rate may be lower, since these figures don’t take into account the fact that Kenyans often have more than one phone line from different service providers.)

And while other countries’ postal services have suffered because of mobile phones and internet usage, Kenya’s postal traffic has actually expanded. The number of private and public post offices and outlets has more than doubled (pdf, p.35) since 2010. Most recently, the number of letters sent between July and September last year, jumped to 17.2 million from 16.6 million in the previous quarter. The Communications Authority attributed this to the number of “success cards,” letters wishing students success in their exams in the fall.

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