Clean tanker description updated

The following daily and monthly average codes have had their size, frequency, and decimal places updated.

From: DISP SYMBOL BATES DEC FREQ CURR UOM DESCRIPTION TC PFAMH00 u 0 DA UNS WSC Clean UK/Cont WAfrica 25KT TC PFARO03 c 0 MA UNS WSC Cln UK/Cont W Afr 25KT Mthly

TO: DISP SYMBOL BATES DEC FREQ CURR UOM DESCRIPTION TC PFAMH00 u 0 DW UNS WSC Cln UKC-WAfr 30KT(x-25) TC PFARO03 c 2 MA UNS WSC Cln UKC-WAfr 30KT MAvg (x-25)