Is the debt higher in 1998 or in 2023-Does it cost more to finance the debt in 1998 or in 2023? Why?

DSA – Debt Sustainablity Analysis

Then you have to answer the following two questions:

1) What is the sign (+ or -) of the contribution of GDP to the change in the debt ratio in 2020? Why?

2) Is the debt higher in 1998 or in 2023? Does it cost more to finance the debt in 1998 or in 2023? Why?

In case you need help the book used in class is the following one: International Economics: Theory and Policy (Pearson Series in Economics)
Paul R. Krugman, Maurice Obstfeld, Marc Melitz