The number of enforced returns by country of nationality is published in table rt_04 (Volume 3 - Returns data tables where returns are broken down by country of nationality and the destination to which an individual is returned to) in ‘Immigration Statistics, July - September 2017’, available from the Home Office website at:
The term 'deportations' refers to a legal definition of a specific set of returns. Deportations are a specific subset of returns which are enforced either following a criminal conviction or when it is judged that a person’s removal from the UK is conducive to the public good. The deportation order prohibits the person returning to the UK until such time as it may be revoked. Published information on those deported is not separately available. As such, the question has been interpreted as referring to enforced returns. In an enforced return, it has been established that a person has breached UK immigration laws and / or has no valid leave to remain in the UK. They have declined to leave voluntarily and the Home Office enforces their departure from the UK.