teeda(extention)のGridのwidth指定でエラー

Gridって便利（っぽい）んだけど、
以下エラーが出た。
%指定はだめですか・・・

というか、css使えって話ですかorz

<table id="articleGrid" width="80%" border="1"> とするとエラー For input string: "80%" <div style="font-size: x-small; font-family: monospace;"><span style="color: red;">java.lang.NumberFormatException: For input string: "80%"</span><br/>  at java.lang.NumberFormatException#forInputString (NumberFormatException.java#48)<br/>  at java.lang.Integer#parseInt (Integer.java#456)<br/>  at java.lang.Integer#parseInt (Integer.java#497)<br/>  at org.seasar.teeda.extension.render.html.THtmlGridRenderer#toDigit (THtmlGridRenderer.java#888)<br/>  at org.seasar.teeda.extension.render.html.THtmlGridRenderer#setupTableSize (THtmlGridRenderer.java#809)<br/>  at org.seasar.teeda.extension.render.html.THtmlGridRenderer#getGridAttribute (THtmlGridRenderer.java#798)<br/>  at org.seasar.teeda.extension.render.html.THtmlGridRenderer#encodeHtmlGridChildren (THtmlGridRenderer.java#221)<br/>  at org.seasar.teeda.extension.render.html.THtmlGridRenderer#encodeChildren (THtmlGridRenderer.java#215)<br/>  at javax.faces.component.UIComponentBase#encodeChildren (UIComponentBase.java#339)<br/>  at org.seasar.teeda.core.util.RendererUtil#renderChild (RendererUtil.java#323)<br/>  at org.seasar.teeda.core.util.RendererUtil#renderChildren (RendererUtil.java#337)<br/>  at org.seasar.teeda.core.util.RendererUtil#renderChild (RendererUtil.java#325)<br/>  at org.seasar.teeda.core.util.RendererUtil#renderChildren (RendererUtil.java#337)<br/>  at org.seasar.teeda.core.util.RendererUtil#renderChild (RendererUtil.java#325)<br/>  at org.seasar.teeda.core.util.RendererUtil#renderChildren (RendererUtil.java#337)<br/>  at org.seasar.teeda.extension.render.TViewRootRenderer#encodeBegin (TViewRootRenderer.java#142)<br/>  at javax.faces.component.UIComponentBase#encodeBegin (UIComponentBase.java#330)<br/>  at javax.faces.component.UIViewRoot#encodeBegin (UIViewRoot.java#100)<br/>  at javax.faces.webapp.UIComponentTag#encodeBegin (UIComponentTag.java#240)<br/>  at javax.faces.webapp.UIComponentTag#doStartTag (UIComponentTag.java#177)<br/>  at org.seasar.teeda.extension.taglib.TViewTag#doStartTag (TViewTag.java#98)<br/>  at org.seasar.teeda.extension.html.processor.ElementProcessorImpl#processTag (ElementProcessorImpl.java#145)<br/>  at org.seasar.teeda.extension.html.processor.ElementProcessorImpl#process (ElementProcessorImpl.java#138)<br/>  at org.seasar.teeda.extension.html.processor.ElementProcessorImpl#process (ElementProcessorImpl.java#119)<br/>  at org.seasar.teeda.extension.html.impl.HtmlViewHandler#renderView (HtmlViewHandler.java#164)<br/>  at org.seasar.teeda.extension.html.impl.HtmlViewHandler#renderView (HtmlViewHandler.java#144)<br/>  at org.seasar.teeda.core.lifecycle.impl.RenderResponsePhase#executePhase (RenderResponsePhase.java#39)<br/>  at org.seasar.teeda.core.lifecycle.AbstractPhase#execute (AbstractPhase.java#57)<br/>  at org.seasar.teeda.core.lifecycle.LifecycleImpl#render (LifecycleImpl.java#131)<br/><br/></div>