/**
@fn obj::last_grace
@section Use
<table>
	<tr>
		<th>Type(s)</th>
		<th>Description</th>
	</tr>	<tr>
		<td>
@ref page_type_158
		</td><td>    The &lt;attenuation&gt; value reduces the diseases' &lt;infectiousness&gt;
    every time it infects someone new. This limits how many generations
    a disease can propagate.</td>
	</tr>

*/