diff --git a/cmd/data2json/data2json.go b/cmd/data2json/data2json.go
index 3459d7f..07a3a6d 100644
--- a/cmd/data2json/data2json.go
+++ b/cmd/data2json/data2json.go
@@ -13,17 +13,19 @@ import (
 )
 
 type Data struct {
-	Year       int    `json:"year"`
-	Week       int    `json:"week"`
-	First      string `json:"first"`
-	Last       string `json:"last"`
-	Period     int    `json:"period"`
-	Start      string `json:"start"`
-	Algemeen   *Parts `json:"Algemeen"`
-	Groningen  *Parts `json:"Groningen"`
-	Amsterdam  *Parts `json:"Amsterdam"`
-	Literatuur *Parts `json:"Literatuur"`
-	Vlaanderen *Parts `json:"Vlaanderen"`
+	Year       int            `json:"year"`
+	Week       int            `json:"week"`
+	First      string         `json:"first"`
+	Last       string         `json:"last"`
+	Period     int            `json:"period"`
+	Start      string         `json:"start"`
+	Max        int            `json:"max"`
+	Sources    map[string]int `json:"sources"`
+	Algemeen   *Parts         `json:"Algemeen"`
+	Groningen  *Parts         `json:"Groningen"`
+	Amsterdam  *Parts         `json:"Amsterdam"`
+	Literatuur *Parts         `json:"Literatuur"`
+	Vlaanderen *Parts         `json:"Vlaanderen"`
 }
 
 type Parts struct {
@@ -88,8 +90,9 @@ func main() {
 		x(fmt.Errorf("ongeldige week: %d", week))
 	}
 
-	start, first, last := dates()
+	start, first, last, names := dates()
 
+	max, sources := makeCounts(names)
 	data := &Data{
 		Year:       year,
 		Week:       week,
@@ -97,6 +100,8 @@ func main() {
 		Last:       last,
 		Period:     size,
 		Start:      start,
+		Max:        max,
+		Sources:    sources,
 		Algemeen:   makeParts("Algemeen"),
 		Groningen:  makeParts("Groningen"),
 		Amsterdam:  makeParts("Amsterdam"),
@@ -107,7 +112,6 @@ func main() {
 	b, err := json.Marshal(data)
 	x(err)
 	fmt.Println(string(b))
-
 }
 
 func makeParts(source string) *Parts {
@@ -163,7 +167,43 @@ func makeValues(source, part string) [][5]any {
 	return v
 }
 
-func dates() (start, first, last string) {
+func makeCounts(names []string) (int, map[string]int) {
+	max := 0
+	counts := make(map[string]int)
+	x(os.Chdir("/net/corpora/nlnieuws"))
+	files, err := os.ReadDir(".")
+	x(err)
+	for _, file := range files {
+		if !file.IsDir() {
+			continue
+		}
+		filename := file.Name()
+		if filename[0] < 'A' || filename[0] > 'Z' {
+			continue
+		}
+		count := 0
+		for _, name := range names {
+			files2, err := os.ReadDir(filename + "/" + name)
+			if err != nil {
+				continue
+			}
+			for _, f := range files2 {
+				if n := f.Name(); strings.HasSuffix(n, ".xml") {
+					count++
+				} else if strings.HasSuffix(n, ".skip") {
+					count--
+				}
+			}
+		}
+		counts[filename] = count
+		if count > max {
+			max = count
+		}
+	}
+	return max, counts
+}
+
+func dates() (start, first, last string, names []string) {
 
 	// 1 januari
 	t := time.Date(year, 1, 1, 12, 0, 0, 0, time.UTC)
@@ -182,7 +222,20 @@ func dates() (start, first, last string) {
 	t2 := t.AddDate(0, 0, 6)
 	tStart := t.AddDate(0, 0, (1-size)*7)
 
-	return makeDate(tStart), makeDate(t), makeDate(t2)
+	names = make([]string, 0)
+	t3 := tStart
+	for range size {
+		y, w := t3.ISOWeek()
+		names = append(names, fmt.Sprintf("%d/%02d", y, w))
+		t3 = t3.AddDate(0, 0, 7)
+	}
+	t3 = tStart
+	for range 7 * size {
+		names = append(names, fmt.Sprintf("%d/%02d/%02d", t3.Year(), t3.Month(), t3.Day()))
+		t3 = t3.AddDate(0, 0, 1)
+	}
+
+	return makeDate(tStart), makeDate(t), makeDate(t2), names
 
 }