What is the best indicator of happiness?

Are we happy? How do we know we are, then? Can we rate our happiness on a scale of 1-10? Does being happy mean that we are always content, or that we can feel sadness or even anger at times? Do people go about trying to achieve happiness in the wrong way? I know there is a relationship between poverty and depression. But is there one for happiness and wealth? Please try to answer all questions I am extremely curious