Since 2003-04 statistics on farm diversification have been collected through the Farm Business Survey. Prior to this, diversification figures were collected through the June Survey of Agriculture. The two surveys are not directly comparable.
Indications from the Farm Business Survey are that, since 2003-04, the percentage of farms that have diversified their business into activities outside food production has remained stable at around 50 per cent. Detailed figures can be found on the DEFRA website.