Red Velvet, a contract manufacturer for medical devices, uses a two-step process to assemble insulin pumps for customer, Tedtronic. Line inspector, Irene, observed that out of the 150 units that were entered into the process at step 1, 90 units were completed defect-free, with the rest sent to the rework department. In the second step, 81 of the 90 units were completed defect-free, and 9 were sent to the rework department. Indicate, showing your calculations, what is the Yield of step 1 (ONLY step 1). Please give your answer in percent (e.g., 98.25%) rounding to 2 places after the decimal.