Hello - Can someone explain what the two numbers in parentheses (47:94) after the plateau numbers are? I've found explanation for everything else in the CGMiner display but this. Thanks!

USB management Pool management Settings Display options Quit
0: GSH 10033649: BM1387:02+ 200.00MHz T:200 P:200 (47:94)  |  100% WU:100% | 42.34G / 45.23Gh/s WU:631.9/m
1: GSH 10033593: BM1387:02+ 200.00MHz T:200 P:200 (47:94)  | 99.5% WU: 99% | 45.65G / 44.91Gh/s WU:627.4/m[/s]