Translate the following English sentence to French:
"Between 1990 and 1997 the volume of transport of goods increased by 21% whilst over the same period the proportion of freight transported by rail dropped by 7%."
De 1990 à 1997, le transport de marchandises a augmenté de 21 % alors que, dans le même temps, le fret ferroviaire a baissé de 7 %.