6 Gross rental income and service charge income
| | 2014 | 2013 |
| Theoretical rent | 163,179 | 159,197 |
| Incentives | (1,431) | (1,226) |
| Vacancies | (5,699) | (5,738) |
| Total gross rental income | 156,049 | 152,233 |
Download XLSThe Fund leases its property investments in the form of non-cancellable operating leases. The nature of the theoretical rent has an indefinite duration because there are no fixed contract periods.
Service charge income represents € 4.0 million (2013: € 2.8 million) income receivable from tenants for the services of utilities, caretakers, etc. when the Fund acts as principal.