Okay, maybe Lowu is higher. But not much more, and probably even. According to the HK government 88 million use Lowu in 2008-9, while 95 million use it in 2007-8, and slightly lower in 2006-7.

Meanwhile, I can't find info on the Macau Government site, but wikipedia says 76 million use the Gongbei port in 2006.

With more crossings opened between HK and China and more hotels and casinos completed in Macau since 2006...

Again, it is exactly because it's all foot traffic between Macau and China that so many people go back and forth each day, because there is ZERO cost. Unlike from HK, where you have to take the train, and it is not cheap. One stop from Sheung Shui to Lowu costs $19.5 using Octopus.