70 active on average at any given time per the article, which then lists total fleet size, as opposed to number of active cars on average, so it's not a fair comparison.
Although then it says they drive about 4m miles per week, which works out to 57,000 miles per active RA agent per week. A person driving ~25 mph on average 24/7 would do ~4000 miles in a week (and we can assume 24/7 here because they reported active agents, so we assume a team of ~3 people swapping out as driver in this hypothetical).
So that gives you a car/operator ratio of at least 14, and probably more since I bet the average speed is less than 25 mph.