The number of security cameras on New York City buses has more than doubled since last summer, and some drivers – afraid of an attack – are packing Mace, New York Daily News reports.

Between January 2010 and July 10, 2013, riders have physically attacked MTA drivers 313 times, according to Metropolitan Transportation Authority statistics. Each month, on average, seven drivers are slapped, punched or even stabbed while on duty.

The assault statistics do not include the not uncommon incidents of drivers being spat on.

Since last July, the number of buses with security equipment has grown from 500 to 1,210, an MTA spokesperson said. That accounts for approximately 21 percent of the fleet. By early 2014, that number is expected to grow to 1,576 (27 percent).

However, for some bus drivers, not much has changed since Edwin Thomas, a Brooklyn bus driver, was stabbed to death by an ex-con fare-beater in 2008. About 80 drivers attended a rally July 11 organized by Transport Workers Union Local 100. Angry drivers want the MTA to move more quickly with the installation of cameras and safety partitions. They’re also calling on the NYPD to routinely have officers ride buses.