Listview Drops To The Bottom

I am using the following layout. Basically, it has a custom toolbar, a Navigation Drawer, a menu, a ListView (listView1), and adlay.

<RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="@android:color/white">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:background="@android:color/black"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
            app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"/>

        <android.support.v4.widget.DrawerLayout
            android:id="@+id/drawer_layout"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_below="@+id/toolbar">

            <LinearLayout
                android:id="@+id/content_frame"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical">

                <ListView
                    android:id="@+id/listView1"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:layout_gravity="start"
                    android:layout_weight="1"
                    android:cacheColorHint="#00000000"
                    android:divider="@android:color/transparent"
                    android:dividerHeight="3dp">
                </ListView>

                <LinearLayout
                    android:id="@+id/adlay"
                    android:layout_marginTop="10dp"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:orientation="vertical">

                    <TextView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:text="Your Adlay Layout"/>
                </LinearLayout>
            </LinearLayout>

            <ListView
                android:id="@+id/drawer_list"
                android:layout_width="240dp"
                android:layout_height="match_parent"
                android:layout_below="@+id/toolbar"
                android:layout_gravity="start"
                android:background="#fff"
                android:choiceMode="singleChoice"
                android:divider="#eee"
                android:dividerHeight="1dp">
            </ListView>
        </android.support.v4.widget.DrawerLayout>
    </RelativeLayout>