OP's line is capable of 18-19 Meg Sync, well within advertised speed, which is always of sync.
But OP has fallen into common trap of confusing throughput with sync.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 19 Meg WBC