A map shows that the vertices of a backyard are $W\left(-100,-70\right),\ X\left(-100,0\right),\ Y\left(0,0\right),$ and $Z\left(-60,-70\right)$ . The coordinates are measured in feet. The line segment $XZ$ separates the backyard into a lawn and a garden. The area of the lawn is greater than the area of the garden. How many times larger is the lawn than the garden?