Reality star and beauty mogul Kylie Jenner situated herself as a force in the makeup market, with her lip kits reportedly bringing in millions of dollars since their initial launch in 2015. But the figure may be significantly higher than previously estimated, as famous Kardashian momager Kris Jenner revealed retail sales of Kylie Cosmetics products to be at $420 million in just 18 months on the market.

Read: Kylie Jenner's Potential Net Worth Could Make Her The Richest 'Kardashian'

The figure was revealed to WWD in an interview with Kris Jenner at her Los Angeles home last week and was published Tuesday. WWD called it “the first time the Jenners have disclosed the scale of Kylie’s business,” and Kris Jenner reportedly provided “documentation” to support the claim. Comparing Kylie Cosmetics with other industry leading brands, WWD pointed out the significance of the brand’s swift rise to the top:

“For perspective, the Estée Lauder Cos. Inc.-owned Tom Ford Beauty was said to have reached revenues of $500 million after a decade, and the brand is considered to be one of the two fastest growing in Lauder’s portfolio, along with Jo Malone. Bobbi Brown, also part of the Lauder stable, took 25 years to reach the billion-dollar mark in 2016, with L’Oréal’s Lancôme finally hitting the milestone in 2015 after 80 years.”

The 19-year-old’s many successful entrepreneurial endeavors — including clothing lines, brand endorsements and multiple reality TV shows to which she’s currently tied — made her youngest person to land on Forbes’ list of The World’s Highest-Paid Celebrities earlier this year. Kylie Jenner is estimated to have a net worth of approximately $18, while her older sister Kim Kardashian has an estimated net worth of $51 million. Given the trajectory of the starlet’s businesses, Kylie Jenner could be well on her way to becoming the richest among her Kardashian sisters.

Read: Kardashian And Jenner Sisters React To 'Life Of Kylie' Premiere On Social Media

Kylie Jenner previously spoke with Refinery 29 about the launch of her eponymous line of cosmetics and told the website that her love of lip kits and liners spurred her interest in starting a brand of her own.

“I’ve been obsessed with lipliners and lipsticks and I can’t leave the house without them, so probably just my obsession with it,” she said of founding Kylie Cosmetics.

“It’s all me and I literally went to the factories and sat with the chemists,” she continued. “There wasn’t really a struggle, it was just the waiting process [that was hard] and figuring out what exactly people would like and what would be on trend a few months later, but I just followed my heart I was sitting there. I would give them an idea of what I wanted, they would make it, then I would try it on and be like ‘Oh it needs more gray, or more pink.' Then they go back, make it right in front of my face. It was dope.”