66/73 as a percentage is 90.41%. This means that the fraction is just a little under one whole, and when you write it as a percent you get a number close to 100%.
The fraction 66/73 shows how many parts out of a total of 73 are being considered—66 parts, to be exact. Because the numerator is fairly large compared to the denominator, the resulting value is high, landing in the low nineties when expressed as a percent.
In everyday situations, a result like 90.41% can represent a strong performance, such as a test score or a success rate. It tells you that the outcome is well above average, but still short of a perfect score.