The National Theatre’s income rose from £98 to to £124m as the charity celebrated its 50th anniversary, according to its recently published annual accounts.

Box office income rose by £15m from £50m in 2013 to £65m in 2014 with the number of people seeing the national theatre productions increasing from 3.6m to 4.5m. Voluntary income rose from £34.3m to £47.6m, large as a result of an increase in capital grants for long-term projects.

In total, the charity received £26.1m in the year for its long-term projects funds.

The National Theatre is in the middle of an £80m redevelopment project, NT Future, which is due to be completed in March 2015. £8.5m was raised towards the project in 2013/14, bringing the fundraising total to £76m.

Total expenditure was £103m for the year end March 2014, up by £12m on the previous year.

For the year ending March 2014 National Theatre paid 39 members of staff more than £60,000, with the highest paid employee earning up to £180,000.

Nicholas Hytner, director of the National Trust, is to step down in March 2015. Rufus Norris will become the next director and Tessa Ross has been appointed to the new role of chief executive.