Formula to work out time elapsed based on a UK tax year

Hey all,

I am currently working on a spreadsheet where I want it to work out the years elapsed from when the person arrived in the UK, however the time elapsed will be based on the UK financial year (6th April - 5th April) and it is not as easy as using the formula: =YEAR(TODAY())-YEAR(A1)

For example...

Say John arrived on 01/01/2014 (in the 13/14 tax year) he would of been deemed to have 1 years UK residency once that tax year has finished (5th April 2014) and then after that he would have another years residency if he was in the UK from 6th April 2014 to the 5th April 2015 - therefore the cell should display 2.

Simply I want the formula to count the date that they arrived in the UK up to the end of the tax year that they arrived in as one year residency and then each tax year after that as another year of residency.

Hope this all makes sense and thank you in advance for any assistance with this, it is greatly appreciated.

Matt