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 and the Universal Music Group respectively. "Good Girl Gone Bad" received generally favorable reviews from music critics. At Metacritic, which assigns a normalized rating out of 100 to reviews from mainstream critics, the album received an average score of 72 based on 17 reviews. "Uncut" called it a "shiny, trans-atlantic blend of Europop vim, R&B grit and Caribbean bounce." Andy Kellman of AllMusic deemed it quintessential pop music and said each of its tracks was a potential hit. Quentin B. Huff of PopMatters praised the album, describing it as "more raw, perhaps edgier and more risqué" than Rihanna's previous material.