Remove background-attachment:fixed;
from your styling.
background-attachment: fixed means that the background is fixed with regard to the viewport. Even if an element has a scrolling mechanism, a ‘fixed’ background doesn't move with the element.
Here is a demo to show you the problem. When the images are lower in the page you cannot see them. As you scroll down you can see the images:
HTML
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Voluptatum deleniti dolor debitis iste eligendi reprehenderit voluptate dignissimos velit tempora quidem molestias tenetur accusantium ea repellendus atque neque minima quos sed!
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Voluptatum deleniti dolor debitis iste eligendi reprehenderit voluptate dignissimos velit tempora quidem molestias tenetur accusantium ea repellendus atque neque minima quos sed!</p>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Voluptatum deleniti dolor debitis iste eligendi reprehenderit voluptate dignissimos velit tempora quidem molestias tenetur accusantium ea repellendus atque neque minima quos sed!</p>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Voluptatum deleniti dolor debitis iste eligendi reprehenderit voluptate dignissimos velit tempora quidem molestias tenetur accusantium ea repellendus atque neque minima quos sed!</p>
<div class="information"></div>
<div class="information"></div>
<div class="information"></div>
<div class="information"></div>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Voluptatum deleniti dolor debitis iste eligendi reprehenderit voluptate dignissimos velit tempora quidem molestias tenetur accusantium ea repellendus atque neque minima quos sed!</p>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Voluptatum deleniti dolor debitis iste eligendi reprehenderit voluptate dignissimos velit tempora quidem molestias tenetur accusantium ea repellendus atque neque minima quos sed!</p>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Voluptatum deleniti dolor debitis iste eligendi reprehenderit voluptate dignissimos velit tempora quidem molestias tenetur accusantium ea repellendus atque neque minima quos sed!</p>
CSS
.information {
position: relative;
display: inline-block;
vertical-align: top;
top: 0;
width: 45%;
margin-left: 20px;
background: #fff;
height: 160px;
background-color: #eeeeee;
background-image:url("http://lorempixel.com/400/200/");
background-repeat:no-repeat;
background-attachment:fixed;
background-position:left top;
margin: 10px;
}