The text doesn't provide clear evidence to either support or contradict this conclusion.
Typically, in most critical thinking assessments, the lack of sufficient data would lead to the conclusion of "Insufficient Data."
However, in the Inference section of the Watson Glaser test, it's acceptable and recommended to apply common knowledge.
Given that over half of the growth in the number of virtual employees in the past five years occurred in the last two years (representing 39% out of 74%), it's a reasonable assumption that the increase in the last year surpassed that of four years prior.
It's important to note that this conclusion is not directly stated in the text, yet it is more likely than not, thus categorizing it as "Probably True."