When Are We At Our Happiest?

I found an online article explaining when we're at our happiest and why. http://www.ageuk.org.uk/health-wellbeing/keeping-your-body-healthy/is-this-the-happiest-time-of-your-life/

Apparently from our mid 40's up we're gradually getting happier until we're happiest after the age of 70 and we reach the peak of happiness whilst in our 80's. Teens and 20's are averagely happy but it declines until we reach our 40's. Obviously it isn't this way for each individual but it is a proven statistic for the average population.

I want to make a short questionnaire and ask random people to fill it out during my next visit in Manchester, I'll ask people from all walks of life and of all ages. I will ask for their age, what makes them happy, and what has been the happiest moment of their life. I want to compare what makes people happy to try and find some patterns and trends.