That roughly 60B dollars for Tanzania.
Kenya transacted around 20B dollars in 3rd Q of 2018 alone. Kenya mobile transactions (p2p & mobile commerce) I think matched GDP from 2nd Q of this year when it hit 19B dollars.
https://ca.go.ke/mobile-money-transfers-hit-ksh-2-trillion-as-penetration-shoots-to-100-per-cent/
2017 Kenya mobile money transactions value
Q1 - 11.7B
Q2 - 12.3B
Q3 - 16.5B
Q4 - 17.6B
Total for 2017 - 58B dollars
2018 Kenya Mobile Transactions value
Q1 -18B
Q2 - 19B
Q3 - 20B
Q4 - .? - not yet released.
So going by that trend - you can expect Q4 to be around 21-22B.
The total for last year[2018] will be around
80B - when GDP is expected to be around 90B.
This year 2019 is when mobile money transactions will probably exceed GDP annually . You're looking at more than 100B dollars.
And not this doesn't include mobile lending data - from more than 50 digital credit providers - who already have exceeded the normal banking loans to households.
Safaricom recently launched an overdraft facility - that has also flown off the shelf - netting more than 1B kshs in a week!
Kenya will continue to be global leader in mobile money. Tanzania is not doing badly. And so are Zimbwabwe & even Uganda.