And the cost of policing the events, one of which is attended by up to 100,000 people, has dropped by £250,000.
However, city centre residents and companies remain unhappy about the impact the parades have on business and qualify of life.
Two years ago, the city council introduced a new code of conduct covering public processions.
In July, it carried out widespread consultation on how the new rules were working. Tomorrow, councillors will consider a report on the findings.
In 2009/10, there were almost 500 parades through Glasgow but, within two years, the number had fallen to 362, a decrease of more than 27%.
While the council says the reduction is welcome, the public believes there are still too many marches, with about two thirds of people who responded being in favour of a further cut.
The report says: "Retail and transport respondents have indicated there is quantifiable evidence of reduced trade and income and increased operating costs at certain times that can be attributed to the impact of parading in the city centre.
"While the right of free assembly was recognised, it was also recognised this needed to be balanced by the rights of residents and businesses to not face undue disruption to their lives.
"The council requires to seek to strike a balance between the legitimate rights of organisers of public processions to freedom of expression and the rights of the broader community to the peaceful enjoyment of their home and family life, their leisure hours and access to their place of business."
Under current legislation, the council is not allowed to impose a blanket ban on parades in any one area.
It has tried to resolve the problem by persuading the organisers of big marches to relocate to city parks.
But some groups have been unhappy about using the parks, citing history and culture and because the council insists they pay for cones and barriers, toilets and arrangements to prevent littering.
By far the largest march through Glasgow is the Orange Order's Annual Boyne Parade, although this year there were 50 individual walks each with about 8000 marchers.
In the past couple of years the Orange Order has introduced an extensive training programme for its stewards, resulting in the number of police needed on march days being cut.
Robert McLean, executive officer of the Grand Orange Lodge Of Scotland, said: "Since the policy was introduced our parades in the city have decreased almost 32%.
"Our stewards are now trained by police, which lets the police leave the parades and deal with anti-social behaviour from the hangers-on who cause the problems."
The Orange Order held 172 Glasgow parades last year, but Mr McLean said only four were in the city centre, with the remainder being held in other parts of the city.
He said: "We don't think we are causing all that much impact on businesses."
Franny McAdam, national organiser of Cairde na hEireann, the main Republican organisation in Scotland, said the number of marches held by the group in Glasgow was "in single figures".
He added: "The council policy is fine and we have no complaints. We are quite happy with it."
Susan Nicol, general manager of the St Enoch Centre, said: "We support the council in relation to the possible impact of processions on the city centre and have outlined our concerns as part of the consultation process.
"When the retail sector is facing a number of challenges, we would be concerned about any developments that might discourage shoppers or visitors from spending time in the city centre."