The area of office buildings leased for personal use varies building-by-building, and generally it is difficult to determine what percentage of a property is for personal use, so it is safest to judge by comparison. Buildings that have come up with a way to judge this assume that the area used for personal use is less than 50%. The exact terms of leases will be explained later as features of buildings vary depending on the area they are in located in, the type of location, and how long ago they were built. Originally in Korea, the terms of rent were decided by something called the jeonse price. In the case of office buildings, jeonse is made up of a deposit of 20%-30% of the total, while the remaining 70%-80% is set as the rent. Contrary to jeonse is the wolse system in which a tenant pays rent monthly. As of 2005, buildings being established that planned to convert to the wolse were increasing by 1.5%.