A 20 ft thick saturated clay layer is underlain by impermeable granite and overlain by gravel. Using the logarithm of time method for a sample from the middle of the clay layer, it was determined from a 1D consolidation test with double drainage that t50 = 5.2 minutes. The average sample height during the load increment was 0.88 inches. What is the time in years for the clay layer in the field to reach 95% average degree of consolidation?