I can't find this information.
Sorry if this sounds stupid.
In the second year, the £10 interest would be used to calculate the interest you earn in that year. So you would earn 10% of £110. After that year you would have £121 in your account. (£110 x 1.10). You'd have earnt £11 interest.
After 13 years say, you would have £100 x 1.1^13, £345ish.
As regards interest rates, at the moment anything more than 3% is excellent. You can get a no-notice (eg you can take out money as and when you want, you don't have to give notice unlike say national savings) savings account with Smile (Co-Operative Bank) at www.smile.co.uk that pays 2.5%. Pretty good in current conditions.
Any questions I'll try and help.