Why does Finland get bigger each year?

Finland is gradually increasing in size due to the process of post-glacial rebound. After the last Ice Age, the weight of the ice sheets caused the land to sink, but as the ice melted, the land began to rise. This uplift continues today, at a rate of about 9 millimeters per year in some areas, causing Finland to expand and reclaim land from the sea. Additionally, sediment deposition from rivers and other geological processes can also contribute to the gradual increase in land area.