Well wishers hold a placard as they gather to wish former President Nelson Mandela happy birthday outside the Medi-Clinic Heart Hospital, where he is being treated, in Pretoria July 18, 2013. Anti-apartheid hero Nelson Mandela is "steadily improving", South Africa's government said on Thursday as the former president celebrated his 95th birthday in hospital amid tributes from around the country and the world. [Photo/Agencies]