The indoor pool at the local YMCA uses a filtration system to keep the pool water clean. The system requires that the filer be backwashed when the discharge pressure for the water pump reaches 25 psi. The average time between backwashing is 10 days and this time period follows an exponential probability distribution. What is the probability that the next backwash will occur between 6 and 9 days after the prior backwash? Answer in four decimals and not as percentage.