TickX
Based on an example from Observable Plot, this chart shows the age distribution of the population in each US state as horizontal ticks. The x position of each tick represents the share of the state's population in that age group.
<Plot
x={{ grid: true, percent: true }}
y={{
// in age order
domain: [...new Set(stateage.map((d) => d.age))]
}}>
<RuleX data={[0]} />
<TickX data={stateage} y="age" x="pop_share" />
</Plot>