Just rough numbers of the top of my head: heaters get replaced after around 20 years as is required by e.g. German law. Gas/heat pump has an around 50/50 split

Just rough numbers of the top of my head: heaters get replaced after around 20 years as is required by e.g. German law. Gas/heat pump has an around 50/50 split for new installations. That would be around 2.5 percent reduction in gas consumption per year. Less affluent EU countries likely have lower numbers.