BROOKLYN - When it comes to subway delays, the F train received failing marks in an annual report. 

According to the Straphangers Campaign, a project of the New York Public Interest Research Group, the F line accounted for 8 percent of all delays across the city, which is slightly more than 300 incidents in 2013. 

The D, Q, R and N trains also made the top 10 list of subway lines with significant delays. However, the J and Z lines were on the opposite end, accounting for just 1 percent of the electronic delay alerts sent out last year.  

The MTA says the alerts are issued in real time to more than 90,000 subway subscribers warning them of incidents that result in significant service problems expected to last more than 8 to 10 minutes. 

Overall, the report shows that most delays were due to mechanical issues, which are up by 51 percent since 2011. Delays in Brooklyn alone rose by 39 percent between 2011 and 2013.