NASA has got good news for us. The world is a greener place today than it was 20 years ago. How does this happen? Well, it appears China and India are leading the change. NASA researchers compared the satellite data from the mid-1990s to today. They found that global green leafy area had increased by five percent since the early 2000s. That's about the same area as the entire Amazon rainforest. 

请问曹老师，这里的had increased 我理解的是用found 做了参照,故用过去完成式.但是整个段落在说过去到现在的对比，我理解的就是绿叶面积增加就是截止到现在的结果，NASA的对比应该也是最近发生的事情，又感觉这里的had increased 有点奇怪，请曹老师指导！