Only 1% of adopted trace their identity via register

The National Contact Preference Register (NACPR), which is run by the Adoption Authority (AAI), was introduced in 2005 on a non-statutory basis and since then has matched a little more than 600 people out of an estimated 60,000 adopted people — a success rate of 1%.
Even when you take into account the fact that a little more than 10,000 adopted people and natural parents have signed up to the register, this success rate rises to just 5%.