Waiting period. Jeff, a local traffic engineer, has designed a new pedestrian foot bridge that is capable of handling the current traffic rate of $260$ pedestrians daily. Once the traffic rate reaches

$2,000$ pedestrians daily, however, the bridge will require a new bracing system. Jeff has estimated that traffic will increase annually at $4\%.$ How long will the current bridge system work before a new

bracing system is required? What if the annual traffic rate increases at $9\%$ annually? At what traffic increase rate will the current system last only $12$ years?

If the traffic rate increases at $4\%$ annually, how long will the present bridge system work before a new bracing system is required?

years $($Round to two decimal places.$)$

If the traffic rate increases at $9\%$ annually, how long will the present bridge system work before a new bracing system is required?

years $($Round to two decimal places.$)$

At what traffic increase rate will the current system last only $12$ years?

$\%($Round to two decimal places.$)$