Adding Throttling

import throttle from 'webpack-worker/throttle.mostRecent'
// ...
  componentDidMount = () => {
    createClient(new Worker('/static/js/worker.bundle.js'), '/sp500hst.txt')
      .then(client => {
        this.worker = throttle.applyTo(client) // apply throttling to API requests
        this.renderGraph(this.state.filter)
      })
  }
// ...