HMRC publish annual statistics of the use of the Social Investment Tax Relief (SITR) scheme. The most recent release is on GOV.UK at: https://www.gov.uk/government/statistics/enterprise-investment-scheme-seed-enterprise-investment-scheme-and-social-investment-tax-relief-statistics-may-2019.
From the introduction of SITR in the tax year 2014-15 up to 2017-18, 80 social enterprises received investment through the scheme, including community benefit societies, charities and community interest companies. Data for the tax year 2018/19 will be published in May 2020.
‘Voluntary organisations’ is not a category used by HMRC to record information in respect of social enterprises using SITR.