Newlands Rugby Stadium in Cape Town has similar steep top tiers, along the wings. In much of "the West" convention dictates the steepest a tier should be is 34 degrees. Some nations may have that built into their building codes. That's why it's rare to see steeper stands beyond balconies. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.