Android - extract duration value in animation list to variable

Question

I face small problem , I need make all duration value one variable to make easy to change as I test many time and I fell its stupid to copy past variable to all items .

<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android"
    android:oneshot="false">
    <item android:drawable="@drawable/penguin1" android:duration="250"/>
    <item android:drawable="@drawable/penguin2" android:duration="250"/>
    <item android:drawable="@drawable/penguin3" android:duration="250"/>
    <item android:drawable="@drawable/penguin4" android:duration="250"/>
    <item android:drawable="@drawable/penguin5" android:duration="250"/>
    <item android:drawable="@drawable/penguin6" android:duration="250"/>
    <item android:drawable="@drawable/penguin7" android:duration="250"/>
    <item android:drawable="@drawable/penguin8" android:duration="250"/>
    <item android:drawable="@drawable/penguin9" android:duration="250"/>
    <item android:drawable="@drawable/penguin10" android:duration="250"/>
    <item android:drawable="@drawable/penguin11" android:duration="250"/>
    <item android:drawable="@drawable/penguin12" android:duration="250"/>

</animation-list>