Xishan District originally planned to afforest 20 hectares last year, but actually afforested 16 hectares. What percentage is the actual afforestation less than the original plan?
西山小区去年原计划造林20公顷，实际造林16公顷．实际造林比原计划少百分之几？
<gadget id="calculator">20 - 16</gadget>
<output>4</output>

<gadget id="calculator">4 / 20</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>