The data you cite ends in 1984, more than three decades ago. Most recent data shows that China is now the largest foreign holder of US debt securities. Quoting Wikipedia:

“As of September 2014, foreigners owned $6.06 trillion of U.S. debt, or approximately 47% of the debt held by the public of $12.8 trillion and 34% of the total debt of $17.8 trillion.[41] As of 2018, the largest holders were China, Japan, Ireland, and Brazil.”

https://en.wikipedia.org/wiki/National_debt_of_the_United_States