Fire crews from Brighton and Hove have tackled almost 6,000 fires in the past five years.
The figures, published this week, show that in the year to the end of March crews from East Sussex Fire and Rescue dealt with 1,030 fires in Brighton and Hove.
The fire service believes that 486 were arson and 512 were accidental while the cause of the other 32 is not known.
From April 2005 to March this year the fire service attended 5,797 fires of which 2,927 – more than half – were started deliberately.
The cause of 2,671 was believed to have been accidental and 199 had an unknown cause.
The figures were made public in response to a freedom of information request on the Whatdotheyknow website.
Tackling fires forms only part of the work of the fire service.
Among other types of incident, they attend hundreds of road accidents each year. They often cut people free from their cars or provide help lifting heavy or awkward vehicles or other objects.
The crews operate from three fire stations in the city, one in English Close, Hove, one at Preston Circus, Brighton, and the other in Roedean Road, Brighton.