Animation: how to get decades as x-axis categories

Dear all,

I really like this
Dear all,

I really like this animation and would like to achieve a similar animation, however with the decades on the x-axis:

import plotly.express as px

df = px.data.gapminder()

fig = px.bar(df, x="continent", y="pop", color="continent",
  animation_frame="year", animation_group="country", range_y=[0,4000000000])
fig.show()

When I add decades to take the place of the “continents”, the animation only shows the decade of the current year.

gap = px.data.gapminder()

cut_bins = np.arange(1950,2010,10).tolist()
cut_labels = [f"{year}s" for year in range(1950, 2000, 10)]

gap['decade'] = pd.cut(gap['year'], bins=cut_bins, labels=cut_labels)

fig = px.bar(gap, x="decade", y="pop", color="continent",
  animation_frame="year", animation_group="country", range_y=[0,4000000000])
fig.show()

Does anybody have an idea how to get all decades on the x-axis so that the values move up as in the example above?