On 1 June 1998, Alice bought a house in Derby for £45,000.

- She occupied the house as her PPR until 1 May 2000 when she left to work in Exeter, living in rented accommodation.

- She returned to the house in Derby on 1 November 2001 and stayed until 1 July 2004 when she left to take up a post in the USA, again living in rented accommodation.

- She returned to Derby on 1 February 2007 and stayed until 1 June 2018 when she bought a house in Nottingham and made this her principal private residence.

- On 1 February 2021 she sold the house in Derby for £164,000.

Compute the chargeable gain.