Bill Gates made his largest gift since the turn of the century, giving away Microsoft Corp. shares that accounted for 5 percent of his fortune, the world’s biggest.

The donation was made in June but became public on Monday and while the recipient wasn’t specified, Gates has made the majority of his donations to the Bill & Melinda Gates Foundation, the charity he and his wife use to direct their philanthropic efforts.

It’s the largest gift of Microsoft shares that Gates has made since 2000. The 61-year-old gave away $16 billion worth of Microsoft shares in 1999 and $5.1 billion a year later, according to calculations by Bloomberg.

According to a review of two decades worth of Gates Foundation tax returns, annual reports and regulatory filings, Bill and Melinda Gates have given a total of about $35 billion of stock and cash since 1994, based on the value of the shares at the time of gifts.

He created the Giving Pledge in 2010 with billionaire investor Warren Buffett, and both have been joined by 168 others who’ve promised to give the majority of their wealth to charity.

In spite of the donation, Bloomberg says Gates remains the richest person on earth with a fortune the Bloomberg Billionaires Index values at $86.1 billion.

Amazon CEO Jeff Bezos whose fortune has risen 30 percent since January 1, briefly overtook Gates to become the world’s richest person last month.