The road building programme was also expanded, with capital expenditure increased to 8% of GDP, "the highest level achieved by any post-war government". Central government expenditure on roads went up from £125 million in 1963/64 to £225 million in 1967/68, while a number of road safety regulations were introduced, covering seat belts, lorry driver's hours, car and lorry standards, and an experimental 70 mile per hour speed limit. In Scotland, spending on trunk roads went up from £6.8 million in 1963/64 to £15.5 million in 1966/67, while in Wales, spending on Welsh roads went up from £21.2 million in 1963/64 to £31.4 million in 1966/67.
Question: By how many millions of pounds did the central government expenditure on roads go up between 1963 and 1968?
Answer: 100; 100