Complex sentence: Since the beginning of coinage in October 1989 to 2004, more than 8.2 million Philharmonics were sold for a total weight of 5.6 million ounces (approximately 174 tons) of gold.
Split into simpler sentences: Since the beginning of coinage in October 1989 to 2004, more than 8.2 million Philharmonics were sold. All of these coins have put together a fine weight of 5.6 million ounces (approximately 174 tons) of gold.