您会计算邮票投资收益率吗？□／卢华朱文投资集邮的人现在越来越多，邮市已成为投资市场。集邮者不仅关注邮品的构成要素，诸如选题、设计、印刷、纸张、票幅和发行量等，更关注它的收益率。那么，邮票投资的收益率如何计算呢？邮票投资收益率的计算公式是：年收益率＝〔... Will you calculate the stamp investment rate of return? □ / Lu Hua Zhu Wen Investment Philatelic people are now more and more, the postal market has become an investment market. Philatelicists are not only concerned with the components of the product, such as the topics, design, printing, paper, ticket and circulation, but also pay more attention to its yield. So, how to calculate the return on stamp investment? Stamp investment rate of return is calculated as: annual rate of return = [...