"In 2017, Cuba welcomed 619,523 American tourists, up 217 percent over 2016, while 453,905 Cubans living in the United States visited their native country, an increase of 138 percent over a year."
Thus, 1,073,428 individuals subject to United States jurisdiction ("American tourists" and "Cubans living in the United States") visited the Republic of Cuba in 2017.
The Ministry of Tourism of the Republic of Cuba (MINTUR) reported visitor arrivals of 4,689,894 in 2017.
Thus, 22% of visitors to Cuba in 2017 were from United States.
Visitors from the United States have the highest net-profit margin to the Republic of Cuba compared to visitors from other countries as visitors from the United States are not purchasing highly-discounted all-inclusive holidays at tourist-focused resorts.