Debt service is about how you manage your debt. There are smart ways to manage debt and dumb ways to manage debt. The longer you stay in the debt, the more you pay because of interest. So it is in your best interest (no pun intended) to pay off your debt early. Keeping that in mind, let's look at the numbers.
Kenya public debt is at 63% of GDP, which is about $50 Billion. Tanzania public debt is almost half of that at 37% which in numbers is $19 Billion. Kenya Debt = $50 Billion, Tanzania Debt = $19 Billion.
Now the Tanzanian budget for this 2019/2020 is $14.5 Billion with 49.6% dedicated to servicing debt--$7.2 Billion. The Kenyan budget for 2019/2020 is $29.7 Billion with 30.5% dedicated to servicing debt--$9.05 Billion.
Assuming that the debt for each country remain fixed (which is unrealistic because of interest rates and new loans), by 2021, Tanzania will have reduced it's public debt by 38%, from $19 Billion to $11.8 Billion. Kenya on the other hand will have reduced it's public debt by only 18%, from $50 Billion to $40.95 Billion.
Assuming everything stays fix, i.e. budget, budget allocations, GDP, debt amount (which again is highly unlikely), KENYA WILL NEED 6 YEARS TO FULLY PAY OFF ITS DEBT. On the other hand, TANZANIA WILL BE ABLE TO DO IT IN LESS THAN 3 YEARS.
That's the difference between smart debt management, and dumb debt management.