Well, let‘s take a look at your situation. What level are your athletes or clients at? New athletes or clients probably would not benefit from percentages as much as more advanced clients, as they need to learn how to perform the lift correctly first and foremost. Second, a new client will adapt to the exercise so fast that by the next time you perform the exercise, their 1 rep max may be out of date and thus their percentages would be incorrect (if they used to bench 100lbs, but after 2 workouts they can bench 110lbs, that 60% you have them working out as now too low to cause the adaptation you are looking for).
Secondly, you can start reading, watching and listening to the news online. News are constantly updated online and provide you ”the edge” when it comes to getting the latest information. If you are only accustomed to read the newspaper every morning, you miss out to compete with the others that know how to use internet to find the latest information.