-1% utilization issue with cudahashcat

[cudanoob]

not sure about why it's reporting -1%, but all the other issues (autotuned to 1, low utilization) indicate you are not giving it enough work to do.

Could I be putting the command in wrong? Here's what I'm putting in. ./cudaHashcat-plus64.bin -m 2500 -r rules/best64.rule /home/ninjabox/test.hccap /path to word list.txt