Defense budget for Russia is set in stone for x amount of years and split between various factors. For 10 years the budget for procurement of weapons is 19T Rubles. So per year thats 1.9T Rubles. But of course not all is spent at once per year due to industry behind in some projects and awaiting parts or development. Thus some money is allocated for the following year. So far, any drop in defense spending is entirely on other aspects like building new military facilities, apartments, etc. Procurement is separated from all those but included in overall defense spending.

Plus Russia has two defense budgets. Military and national security — that is the Rosgvardi.