Edit: thinking about the numbers a bit: there are ~6500 suicide deaths in the UK per year. Samaritans has something like 150 people answering phones 24⁄7 (extremely rough). So if every one of those 6500 people calls (absurd) and if the service improved so much they all survived (also absurd) that’s still only 0.04 lives per person day (taking a day as 8 hours). So I think you have to start there and maybe go down a few OOMs due to those absurdly optimistic assumptions.
Edit: thinking about the numbers a bit: there are ~6500 suicide deaths in the UK per year. Samaritans has something like 150 people answering phones 24⁄7 (extremely rough). So if every one of those 6500 people calls (absurd) and if the service improved so much they all survived (also absurd) that’s still only 0.04 lives per person day (taking a day as 8 hours). So I think you have to start there and maybe go down a few OOMs due to those absurdly optimistic assumptions.