Change Step Size in JS Countup Animation

I have been playing around with variations on this wonderful CodePen example of a JavaScript count-up animation: https://codepen.io/jshakes/pen/KKpjdYv.

I’m interested in changing the step size of the counting action – i.e. counting by 2’s, 3’s, 5’s, etc. instead of by single digits. So far, I have tried changing the value of the frame variable as well as adding values to totalFrames and progress, but am unable to achieve different step sizes. Does anyone have any idea how to go about implementing this? Any feedback is greatly appreciated.

CodePen: https://codepen.io/jshakes/pen/KKpjdYv

HTML

<button onclick="runAnimations()">Animate</button>
<ul>
  <li><span class="countup">45</span></li>
  <li><span class="countup">110</span></li>
  <li><span class="countup">53210</span></li>
</ul>

JS

// How long you want the animation to take, in ms
const animationDuration = 10000;
// Calculate how long each ‘frame’ should last if we want to update the animation 60 times per second
const frameDuration = 1000 / 60;
// Use that to calculate how many frames we need to complete the animation
const totalFrames = (Math.round( animationDuration / frameDuration ) + 5);
// An ease-out function that slows the count as it progresses
const easeOutQuad = t => t * ( 2 - t );

// The animation function, which takes an Element
const animateCountUp = el => {
    let frame = 0;
    const countTo = parseInt( el.innerHTML, 10 );
    // Start the animation running 60 times per second
    const counter = setInterval( () => {
        frame++;
        // Calculate our progress as a value between 0 and 1
        // Pass that value to our easing function to get our
        // progress on a curve
        const progress = easeOutQuad( frame / totalFrames );
        // Use the progress value to calculate the current count
        const currentCount = Math.round( countTo * progress );

        // If the current count has changed, update the element
        if ( parseInt( el.innerHTML, 10 ) !== currentCount ) {
            el.innerHTML = currentCount;
        }

        // If we’ve reached our last frame, stop the animation
        if ( frame === totalFrames ) {
            clearInterval( counter );
        }
    }, frameDuration );
};

// Run the animation on all elements with a class of ‘countup’
const runAnimations = () => {
    const countupEls = document.querySelectorAll( '.countup' );
    countupEls.forEach( animateCountUp );
};