business property corporate tax

Solo Ltd lets out a warehouse which is surplus to requirements. The building was empty from 1 April to 31 July 2020, but was let from 1 August 2020 onwards. The following income and expenditure was received or incurred during the year ended 31 March 20 Date received/paid £ 1 April 2020 Insurance for the year ended 31 March 2021 (920) 1 August 2020 Rent for the six months ended 31 January 2021 7,800 1 August 2020 Security deposit equal to two months' rent 2,600 1 March 2021 Rent for the six months ended 31 July 2021 7,800 ANSWER TO THE ABOVE QUESTION £ Rent receivable £(7,800 + (7,800 ? 2/6)) 10,400 Security deposit 0 Less Insurance (920) Property business income 9,480 DOUBT - In the answer they have adjusted the rent receivable for 8 months but they have taken the insurance for the whole year why haven't they apportioned the insurance for 8 months??