A dual-axis line chart displays two lines. Company A's sales growth is plotted on the left axis with a scale of $1$ unit = $2.0\\text{ mm}$ of vertical height, and has a slope of $5.0$ units/month. Company B's sales growth is plotted on the right axis with a scale of $1$ unit = $0.5\\text{ mm}$ of vertical height, and has a slope of $10.0$ units/month. What is the ratio of the visual slope of Company A's line to Company B's line on the chart?