A bar chart from the Institute for Government of Spending on prisons, 2009/10–2021/22 (2023/24 prices), where spending decreased from £4.4 billion in 2009/10 to £3.56 billion in 2015/16. Spending increased to £4.06 billion in 2021/22, and is forecast to grow to £4.34 billion in 2024/25.