2018-1: Oh Say Can You See?

Imagine standing in front of a line of skyscrapers of varying heights. Assume that you can always see a skyscraper that is taller than a closer skyscraper. For example, a person on the left of the diagram below can see 3 skyscrapers – the first, fourth, and sixth from left to right. In contrast, a person on the right can see 2 skyscrapers – the seventh and sixth.

                                    ┌───┐
                                    │   │
                                    │   │
                                    │   │
                                    │   │
                      ┌───┐         │   │  ┌───┐
                      │   │         │   │  │   │
                      │   │         │   │  │   │
                      │   │         │   │  │   │
                      │   │         │   │  │   │
 ┌───┐  ┌───┐         │   │         │   │  │   │
 │   │  │   │         │   │         │   │  │   │
 │   │  │   │         │   │  ┌───┐  │   │  │   │
 │   │  │   │  ┌───┐  │   │  │   │  │   │  │   │
 │   │  │   │  │   │  │   │  │   │  │   │  │   │
 │ 5 │  │ 5 │  │ 2 │  │10 │  │ 3 │  │15 │  │10 │
─┘   └──┘   └──┘   └──┘   └──┘   └──┘   └──┘   └─

Write code that, given a scalar or vector of skyscraper heights from closest to furthest, will return an integer representing the number of skyscrapers that can be seen.