"study" "year" "event.e" "n.e" "event.c" "n.c"
"MRC-1"   1974        49       615        67      624
"CDP"     1976        44       758        64      771
"MRC-2"   1979       102       832       126      850
"GASP"    1979        32       317        38      309
"PARIS"   1980        85       810        52      406
"AMIS"    1980       246      2267       219     2257
"ISIS-2"  1988      1570      8587      1720     8600
