yAxis_emission = g =>
g
.attr("transform", `translate(${margin.left},0)`)
.call(d3.axisRight(y_emission).ticks(tick_num))
.call(g =>
g
.select(".tick:last-of-type text")
.clone()
.attr("x", 3)
.attr("text-anchor", "start")
.attr("font-weight", "bold")
.text(data.y)
)