The 2013 attack was <1% of total internet traffic for its duration. The 2014 Cloudflare hit was ~2.5% of all traffic. BBC was ~3%, and OVH was ~4%. (Interpolated from Cisco here: http://www.cisco.com/c/en/us/solutions/collateral/service-pr...) Most predictions suggest that IoT attacks will grow faster than what we've already seen, and a rough estimate suggests that DDoS capacity is growing faster than legitimate capacity.
None of that means today was orders of magnitude higher - the shock factor was that it exposed a structural weakness people hadn't accounted for. But I expect this to become an increasingly significant problem as capacity increases, and moreover as that capacity becomes available to more attackers.
