<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 250 100">
<text fill="green" x="10" y="10">
    <tspan style="font-size:10px">1</tspan>
    <tspan style="font-size:6px">2</tspan>
    <tspan style="font-size:1px">3</tspan>
    <tspan style="font-size:0.50px">4</tspan>
    <tspan style="font-size:0.49px">5</tspan>
    <tspan style="font-size:0.10px">6</tspan>
</text>
<text text-anchor="middle" font-size="6pt" x="125" y="50">Font size should decrease monotonic.</text>
</svg>