I only need the answer to the part where it says "determine the amount of Ionis tax revenue for the year"

Attempt 4 Over the past year, Ionia's money supply decreased by $4 billion, $1 billion in bonds were sold to the public, an unused military base was sold for $2 billion, and the government spent $20 billion. Ionia had a budget deficit. surplus. Determine the amount of Ionia's budget surplus or deficit. $ billion Determine the amount of Ionia's tax revenue for the year. billion $