Do you know PageRank is no longer relevant?
A few years ago, PageRank was the best way to track the relevance of a website. However, in 2009, Google had removed PageRank from its Webmaster Tools, saying:
"We've been telling people for a long time that they shouldn't focus on PageRank so much. Many site owners seem to think it's the most important metric for them to track, which is simply not true."
Another fact confirming this is that PageRank indicator was never available in Google's own Chrome browser - launched in 2008.
The visible page rank is now updated very infrequently. The last known update was in November 2013. In October 2014, Matt Cutts announced that another visible PageRank update would not be coming.
Note: Even though "Toolbar" PageRank is less important for SEO purposes, the existence of back-links from more popular websites continues to push a web page higher up in search rankings.