Northwest Natural Gas Company (NYSE:NWN - Get Free Report) Director David Anderson sold 1,500 shares of the company's stock in a transaction that occurred on Friday, September 18th. The shares were sold at an average price of $48.03, for a total value of $72,045.00. Following the transaction, the director owned 49,259 shares of the company's stock, valued at approximately $2,365,909.77. This represents a 2.96% decrease in their position. The sal…