annual revenue doubled to $3.2 million a year, an increase attributed by Roskam to the IPA's campaign against parts of the Racial Discrimination Act and the Gillard government's media regulation proposals. In 2008, former executive director of the IPA Rod Kemp was appointed chair of the IPA. In 2013 the IPA celebrated its 70th anniversary, MCed by political commentator Andrew Bolt. Notable in attendance at the celebrations were: Gina Rinehart Rupert Murdoch Tony Abbott - Liberal Opposition Leader George Pell - Australian Cardinal of the Roman Catholic Church Michael Kroger - then President of the Victorian division of the Liberal Party of Australia and former director of the IPA Mitch Fifield - Liberal Communications Minister Robert Doyle - Liberal Lord Mayor of Melbourne Denis Napthine - Liberal Premier of Victoria In August 2018, Australian Public Service Commissioner John Lloyd resigned during an investigation into correspondence he had with his former colleagues at the Institute of Public Affairs. On the day he retired, the investigation concluded that he had breached the Australian Public Service code of conduct by corresponding with the Institute of Public Affairs, but the breach did not warrant sanction. Lloyd subsequently returned to work at the IPA. In 2018, the IPA held two dinners to celebrate its 75th anniversary. The first was sponsored by Visy and took place on 21 August, the night of the first 2018 Liberal Party of Australia leadership spill. Former prime minister John Howard was interviewed at the dinner by Janet Albrechtsen about the spill, but did not explicitly support either candidate. Gina Rinehart and Rupert Murdoch praised US President Donald Trump at the dinner. The second dinner was hosted by Crown Melbourne in November, and was hosted by Janet Albrechtsen, Andrew Bolt and Brendan O'Neill. Guests included chair of Liberal Party fundraiser the Cormack Foundation Charles Goode; former Cormack board members Hugh Morgan and John Calvert-Jones; Liberal minister Alan Tudge; and Liberal strategist Brian Loughnane. In 2021, in reaction to Victorian Labor Government moves to ban the public display of the Nazi swastika and other hate symbols, Roskam decried the move as "the most vicious attack on free speech ever contemplated anywhere in Australia". Governance and membership The voting members are distinct from the general membership, who numbered 4,559 in 2017. Non-voting membership is open to the public, with membership fees ranging between $22 and $249 as of July 2018. Membership has increased