def create_linechart(df, label, value):
hovertext=df[label].astype(str) + "<br>" + df[value].astype(str) + " million square km",
title=f"<b>Arctic Sea Ice Extent</b><br><span style='font-size: 13px;'>ANNUAL SEPTEMBER MINIMUM EXTENT</span>",
title_font=dict(family="Arial", size=18, color="black"),
xaxis_title_font=dict(family="Arial", size=11, color="black"),
yaxis_title='million square km',
yaxis_title_font=dict(family="Arial", size=11, color="black"),
fig = create_linechart(df, "year", "extent")