German South West African Mark the gold content of the British Pound Sterling was 7.3224 grams, while the gold content of 20 marks was 7.168 grams. According to Gresham's Law, "bad money drives out good", so the "bad" Mark replaced the "good" British Pound Sterling. In 1901, the German Mark became the official currency of German South West Africa, hence replacing the 20 and 5 mark denominations of the German South West African Mark, for which they were also demonetized (although, they continued use in the metropolis of German South West Africa until 1907). In 1923, the coins of the German South West African Mark
Good Girl Gone Bad Pitchfork Media described the opening lyrics of the song as inspired by "puerile psuedoporn". The album concludes with the title track "Good Girl Gone Bad", which is played with an acoustic guitar and click tracks. Released as the lead single from "Good Girl Gone Bad", "Umbrella" was sent to contemporary hit, rhythmic and urban radio in the US on April 24, 2007. The song received acclaim from music critics, who praised its production, vocals and the collaboration between Rihanna and Jay Z. "Umbrella" reached number one in more than seventeen countries worldwide, including on the UK Singles Chart and the