got .exit().remove() to work

public/app.js

@@ -10,11 +10,10 @@ let highlighted = []
 
 const renderTable = () => {
 	const trs = d3.select('tbody')
-		.html('')
 		.selectAll('tr')
-		.data(highlighted, d => d.id)
+		.data(highlighted, d => d.instance_id)
-		.enter()
+	trs.exit().remove()
-		.append('tr')
+	trs.enter().append('tr')
 		.selectAll('td')
 		.data(d => [
 			d.instance_id, 
@@ -24,7 +23,7 @@ const renderTable = () => {
 			`${d.dropped} (${Math.floor(d.dropped/d.total_students*100)}%)`, 
 			d.graduates,
 			`${d.ninety_day_outcomes} (${Math.floor(d.ninety_day_outcomes/d.graduates*100)}%)`
-		])
+		], d => d.instance_id)
 		.enter()
 		.append('td')
 		.text(value => value)