COLOMBIAN INFLATION STABLE AT AROUND 20 PCT Colombia's cost of living index rose 2.71 pct in March, after a 2.03 pct increase in February and a 2.21 pct rise in March 1986, the government statistics institute said. The result brought year-on-year inflation to 20.36 pct compared with 22.65 pct at end-March 1986 and 19.77 pct for the year ending February 1987. The government has predicted that inflation this year would be slightly lower than in 1986 when it reached 20.9 pct.